Hi all, had a fun holiday season and decided to tear down all the spare/bootleg carts I've collected in the last few months, and ended up with the following:
1x PROG42G-1
1x PROGTOP
3x PROGBK1

1x CHA42G-1
4x CHA256

I decided that I'm going to try my hand at making a Ghostlop, Ironclad and Crossed Sword 2 carts given they weren't commercial available (not available on a 161 cart afaik). I have been reading up on the neogeodev wiki and have a general understanding of the idea of the M1/S/V/C/P roms, but cannot find concrete info on stuff like why certain boards have to be used with certain games.

Going off the boardcodes list on JNX, I thought my Crossed Swords 2 cart would end up using the 42G-1's I have, but the board pics on MVS-Scans used a BK1+256 combo. Is there any reason for this other than the general availability of the BK1+256? Likewise, the Ghostlop pics use a GCS+256 combo, does that mean that I cannot use a BK1 board for that game?

Also, I've been trying to wrap my head around the jumpers and ROM divisions. I understand the more straightforward use of a 32Mbit rom for a V1 (as seen with Ironclad), but I noticed the MVS-Scans pic has two 16Mbit roms for V1/V2 instead. Other than splitting the ROM into equal parts, is any other setup required to use multiple chips? Like with Ironclad, the game has 4x32Mbit C-ROMs, is there any reason that I couldn't get away with 8x16Mbit ROMs?

Lastly, I recall reading on the board something around the lines of "swapping pins" for the S or M1 roms - where does that play a role? Is this regarding the usage of a 28-pin dip vs a 32-pin? Or are there peculiarities with certain games that the address pins have to be grounded or tied together?

Any help or information would be greatly appreciated. At this point, I tried to create an Ironclad on a BK1+256 setup, and got the game to boot with garbled graphics/sound. I assume that I failed when programming the ROMs, but figured I might have missed something more basic with understanding how the jumpers and board-types play a role.