This was his advantageous re-life where the new BttF version was practically laid out by Alexander from beginning to end. It would be a waste if they do things sequentially when they could be done simultaneously.

Although filming is still sequential in a sense, simultaneousness pertains to incorporating those sequential filming to entirely make a film trilogy.

It is a great undertaking which could only be done if a lot of preparation has been made. TV shows and any series have done this quite often but everything changes up when it comes to film.

Most TV shows in this era are mostly shot with minimal budget and its premise takes that limitation into consideration. Most of its end results are shoddy but there is a lot that shines out.

Unlike the millions that would be divided throughout an entire season's run for TV shows, films use that divided millions into just a few scenes and the high pay of a movie actor.

When TV shows are satisfied with a few film sets, films have as many as it takes until the director is satisfied with what he's got.

Things like Titanic took quite some time to get going before the true filming process and it could be seen from their how films are an entirely different beast.

Perhaps the most successful example of a film trilogy filmed in one go is Lord of the Rings. However, Peter Jackson has to mobilize a lot of his time just to prepare all that he needs and correlate an expansive novel and condense it into film.

It can be seen from there on how shooting all three films in bulk could prove difficult.

Although each BttF film is much less tedious than the iceberg-crashed Titanic and the fantasy Tolkien world, it is still tedious nonetheless with all the set pieces and timeline changes to be considered.

A lot of preparations need to be in order and the problem that arises would be whether Creed Pictures did a lot of pre-production process or not.

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Alexander had no clear idea on how far his grandfather has prepared yet but he could gauge on the success of the three film ambition by comparing it to what he knows.

Fortunately, he did know quite a lot from all the Back to the Future documentaries and details that are fortunately being masterfully processed by his Mind Mansion.

Just from the Stoltz problem and Fox splitting dilemma's of the original Back to the Future film alone has already shown out the problems of a single film production, how incremental could the problems be when it is multiplied to three.

Alexander may just be negative and critical but all that he gathered from his memory has already made a lot of possible and unwanted red flags.

Even though the past-future didn't employ producing 3 films at once, it did however have done continuous filming of 2 films at once.

It mostly dealt with the last two sequels though and not the standalone filming they had done with part 1.

From what he remembered, preparations for that had taken quite some years before all the Wild West sets, 2015 futuristic neighborhoods, recreating 1955 locations and shots, and dystopian 1985 Hill Valley that was royally biffed by Biff Tannen.

Alexander had no idea how long it took to prepare such an endeavor but he could infer from how far apart the theatrical releases were.

Part 1 came out in 1985 but it was only further along the line in 1989 that Back to the Future II has been released.

It took a period of four years or so and Alexander could reason that out to the meticulous preparation time and script perfecting.

Granted, Bob Gale must have been busy perfecting time travel movies that all come into place while Robert Zemeckis was busy with another filming responsibility called "Who Framed Roger Rabbit?'.

Robert's film about a cartoon and live-action mix could account for extending prep duration but the troubles of screenwriting could very well be the true extendor of it.

Rob was on the rise and busy with things so he could probably only help out seldomly while poor Bob and his legion of screenwriting cohorts had to make things as grand as possible.

As low status the screenwriters have in the industry has, there is no denying that they are essential to making a lot of things happen.

The big problem of writing a sequel is that a lot of considerations need to be coordinated. There is also an established industry trend that most sequels pan out and are nothing compared to the original.

Rob and Bob didn't rush to cash in, rather they wanted everything to tie together and break the industry trend by making their passion films to be a masterpiece.

They did work quite hard on it until their idealized time-travel to the Wild West was too much that they had to cut it into two parts and supplement the split parts that were made lacking.

Filming two films at once wasn't even in their plans in the first place and they just rolled with it.

Of course, that was just the surface deliberation of the sequel preparations as other problems with the making of the sequels popped up.

An actor didn't want to return to his role, so the script needed to be reworked. The said actor is also quite integral to the story so they have to make sure of ways to make him still be present while being absent.

An actress could unfortunately not make it due to problems she has with an immediate family, thus her presence in the script needs to be adjusted.

The main actors have a problem with how this certain part of the story is portrayed and so, the script needs reworking again.

There are also a lot of scenes in the first movie that wasn't quite working out and the sequels need to take that irking scenes as their limitations.

It can be seen that aside from the set and location preparations itself that producing and coordinating many films at once is a difficult endeavor. Just the problem of script making alone is already a nightmare.

Of course, filming complications don't stop there as a sci-fi film like Back to the Future has a lot of usage for special effects and the ILM of 1984 is levels lower than the ILM it would be in 1989.

Just from problems of the original timeline alone, Alexander has already made a lot of potential arguments that could shut down old Sullivan's three-film ambition.

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However, as many the drawbacks and potential limitations he has listed out in his head, there was no denying that Alexander was inclined to such a filming strategy.

He wasn't going to voice out these concerns of his at all but was rather looking forward to how his grandfather has come up with solutions to get around it.