Since I had only checked that the source was compile-able, it looks like there were a few problems with (the last version). I'm going to take some time to perform some maintenance on this.
-It looks as though 1.31 didn't compile correctly so I recompiled it and swapped out the file with 1.32 but the version display still says 1.31, so I'll switch it when I get home.
-Since there were various bugs with 1.30, I hurriedly updated it to 1.31 with a PCM cache test version, but I think that, operationally, this version should be better.
Known Bugs
-PCB versions ms5pcb and svcpcba have a SYSTEM ERROR and don't run. The cause is currently under investigation.
MVS versions mslug5 and svc should work.
(this hasn't been confirmed with 1.31, but it probably hasn't been fixed.)
How To Use
All previous cache files are broken, and you'll need to make new cache files. Please use the romcnv_mvs.exe(Ver.06) included with this file to create them. Also, due to the circumstances, I've stopped zip compressing the cache files.
When you create the cache, a folder called gamename_cache will be created inside romcnv's cache folder. Same as before, copy this folder to MVSPSP's cache folder.
State Of Development, Etc...
-Concerning the topic on 2ch about whether to reconvert all ROM files or to just keep using them as-is, for various reasons it's set up so that current original ROMs and cache can also be used. I have no plans to change this setup in the future.
-There's nowhere near the necessary amount of memory to decode and decrypt on the PSP. Also, the processing power is so low that it would take quite a while to decrypt, so a methoud to use ROMs as-is is impossible.
-If all are converted, barring a change in the implementation, all would have to be uncompressed and the space used on the MS would increase.
-I think that compressing only a portion of files after reconverting all of them would be pointless for the following reason.
Approximately half of the games don't require cache, and cache files are only constructed for a portion of the remaining half, I probably just don't want to separate all the work (laugh)
As Mr. 201 has written, and I'm sure that those who know are already doing this but, none of the sprite ROMs (c1.rom, etc...), PCM ROMs (v1.rom, etc...), and program ROMs (p1.rom, etc...) from the original ROM file are used after conversion so it's possible to delete them.
The files that are ok to delete are the files that are displayed when the cache file is created.
The reason I didn't write this is because I'd get mail saying things like "It doesn't work after deleting" or "please create a deletion tool". Also, please understand that the reason I don't delete these with the tool is because there are those that hate this.
(Since the games you'll be playing are probably limited, I think it's not too much of a problem to just do this on your own...)