One of my goals for DQ1 Remake Build 2.20 was to eliminate all the source of lag spiking noticed in earlier builds, and I discovered what caused most of it.
The user interface code was loading a lot of external assets by default. It looked nice, but unfortunately the code was very inefficient, and the lag spikes were caused by how poorly all that extra information moved in and out of memory.
To fix this, I tossed out the old interface for items/skills/equipment/shops and redid it using simpler code. I also removed some scripts that were loaded into memory but weren't doing anything.
The results have been incredible, with framerate issues hammered down to nil, the improved scripting shows more tactically useful information, and a lot of load bloat is gone, meaning the game starts much faster.
This does have a gameplay change in that only one accessory can be equipped, not two, but I consider this an improvement for game balance, as two accessories of certain types could be a bit overpowered.
This will require players of the older builds start a new save, which is unavoidable, but the trade-off of a far more stable game with much smoother FPS is more than acceptable from where I'm standing.
This will push back my ETA only a little more than I planned, since most of these changes proved very easy to implement, I just need to test some edge case scenarios to make sure no game crashes happen.