If we take this definition and apply it to the IBO Gundams, it does seem to heavily imply that the pilots are given a degree to modify their Gundams.Seto Kaiba wrote: ↑Wed Dec 06, 2017 6:52 pmCustomization refers to replacement of stock parts with non-standard or non-production hardware that either improves the unit's performance or adds new capabilities that it was not originally designed with.
The Gundam Frames were already produced from the start to fight mobile armors, so if they had to take that base and then customize it further, it seems likely that it had to be for specific pilots and/or situations. Especially with that line about the Gundam Frames being something that "emphasizes the personality of the pilot" and such.
This is also in addition to the idea that we can safely presume at this point that each Gundam's external armor parts are mainly individualized to each frame based on the the designs we've seen. This is of course assuming all of them were using their original parts from when they were made (minus Gusion since we know that none of it's current known forms are original). I think the only one we know are still using their Calamity War designs are Asteroth Origin, Barbatos Form 4, Flauros and maaaaaybe Kimaris Vidar.