Ags games for low end device

[NavaronGunner]

Hi everyone, long time fan here
ive been busy lately trying ags games on Retroarch for PlayStation Classic running Autobleem.
Thanks to Kyland, which compile and optimize cores for that minis, i was able to run them all.
The whole Blackwell series is awesome and the first 3 chapter run excellent, sadly when it comes to Blackwell Deception it has choppy sound and run at 10 fps max.
The first 3 games run at 320x240 while last 2 use a higher res so that could be the problem but i dont really know.
What i wanted to ask is a if there is a way to make scummvm run that game with a lower resolutiin or to downgrade graphics from 32 to 16 bit? when use windows theres a winsetup.exe to setup that option but seems like scummvm ignore that acsetup.cfg and run the game as it is