More content courtesy of Neith:
https://gamefaqs.gamespot.com/boards/168653-final-fantasy-vii-remake/77386199/915674097
NeithOF
I translated some parts of the interview that the guy on the TLS forum didn't. Keep in mind this is a rough translation, i am not fluent.
He splits the process of creating a location in 3 parts
Part 1: Interpretation of the locations he is in charge of from the original FF7 game
part 2: Planning modifications/additions and alterations to the location, then getting them approved through meetings as well as deciding how much resources are needed.
part 3: Actually implementing the above, then polishing up the location.
He says that because the story is already decided and the game has a linear progression (story wise) how to design a location depends on the battle scenarios that take part in it, from necessary character motions and actions to how vertical the area must be, the events/setpieces that will take place in the area etc, all are taken into consideration before creating the location
aka they use the original as direct reference on what will happen in each area, then adapt that to the new combat and additional events, taking into account how the characters will move and what actions they will have available etc then they create the location.
During the planning phase of a location they include all the elements that make up the game such as scenario, actions, terrain type, topography.
The resources ordered/asked for each location include everything, from experts on bug stuff, to character designers, scenario writers, cutscene directors, UI designers and motion directors, even texts for NPCs.
Once all this is done they of course can't just implement them arbitrarily, it is necessary to responsibly implement all the resources used and of course there are always issues and shortcomings that will be visible here and there so they promote revisions and when they move forward to the next location they keep in mind "how can we improve even more on this one".
For the above reasons the amount of work constantly gets increased but that is something that can't be helped/is inevitable since that's exactly what allows them to achieve what they really want freely. Even when keeping the games volume in mind the amount of work they have to do for each location seems as if you're making a game from 0 and because of that there is a lot of enthusiasm.
He also confirms that the planning phase for all locations is already settled, they have already entered the "building/making" phase and the locations are already taking shape, and getting closer to how they have imagined them every day.
Last interesting part, he was asked what is the most difficult time during work and he said
"When a great idea doesn't get realized as intended due to technical difficulties which then forces modifications on the initial plan, or when someone else comes up with a brilliant new idea which makes me feel bad for myself for not coming up with it.
Because when you're feeling like you have given all the great ideas you could come up with and then someone else comes with a new overwhelmingly good idea you feel the frustration."