I did eventually upgrade the video memory, but I didn't do a before/after comparison. It's been a while since I have worked on this machine though, but I had purchased the zip ram on eBay in a tube back then. Other than better video modes, I don't think the ram improves performance though. Since it's internally VLB, it's going to be a better video option than an ISA card. I think the resolution and color depth you are looking for would probably work.
Thanks for the offer for the master cd/diskettes. I did find a copy of the original master CD on archive.org, and a working master diskette on another site that had archived them. I just had to go through different format codes before I found the one that worked. I haven't actually tried it on the physical machine, but since it's an emulated system in 86Box I tried it there. For some reason it asked for a password though, so some reverse engineering of the code was needed to determine the password for each format code.
Also, didn't see Monther's earlier questions, so I will put what I know here.
You will need to modify the master diskette to load an IDE driver instead of the included Panasonic port driver to make it work.
Master CD: https://archive.org/details/pb-cd-170131
Master Diskette: https://ryan.thoryk.com/pb-restore/ (I used 141233)
Jumper configuration options I used here: https://stason.org/TULARC/pc/motherboards/P/P … REVISION-B.html
But I don't think I set anything for the video ram.
Hope this helps.