Need help getting PC to output 31khz

[R25th]

Hello everyone!
I've been having the time of my life trying to get this project up and running. I have a HP EliteDesk 705 G3 mini PC with a AMD PRO A10-9700E running Windows 10 that I want to put inside of a Blast City with a J-PAC acting as the bridge. I have gone with Windows 10 because I want to run Final Burn Neo and Flycast as well as a few other programs in addition to GroovyMAME with LaunchBox's BigBox as my front end tying everything together.
I have tried multiple different ways to get this PC to output 31khz through it's VGA port that I have connected to the J-PAC. Note: AMD's Radeon software reports the VGA port as a DisplayPort which may explain things. BUT, I installed CRT EmuDriver 2.0 beta 15 18.5.1 on top of Windows Basic Display Driver as instructed in http://geedorah.com/eiusdemmodi/forum/viewtopic.php?pid=1052#p1052. Installation goes fine but when I go to emulate the EDID within vmmaker, the output dropdown is completely blank. Because the VGA port is hooked up to the J-PAC, Windows reports it as "Wired Display" and vmmaker reports it as "Generic Non-PnP Monitor". I can generate the modes and install them just fine using the Nanao MS-2931 preset but I haven't been able to set the EDID. As such, even though I put Windows in 640x480, the J-PAC only lights the Sync In LED, not the Sync OK with the jumper just set to 31khz (My Blast City has a manual mode switcher so being able to stay in 31lhz mode would be nice). The monitor also just displays noise when hooked up (or rather it shows the image smeared across the screen multiple times, indicative of the sync not working). I have confirmed the monitor works with a cheap multicade board for testing purposes. It should be noted that the APU is listed as supported in CRT Emudriver as a "AMD Pro A-Series APUs with Radeon™ R5 or R7 Graphics" (the PRO A10-9700E has Radeon R7 graphics).
After struggling with vmmaker for a couple of weeks, I tried a few different tactics. I installed the official AMD Radeon software (version 22.6.1) and allowed it to install the appropriate drivers. I then tried to create a custom resolution within the Radeon software but I am having difficulty finding the official numbers needed to run a 31khz arcade monitor and every time I tried I got a "The custom resolution settings are not compatible with this display" error message. I then tried to recreate it in CRU but even just using the 640x480 @ 60hz preset on the "Generic Non-PnP Monitor" would result in the DisplayPort monitor, which was displaying the correct Dell model number in CRU and that I did not touch, would just show a black screen upon reboot, requiring a boot into safe mode and uninstalling the CRU options. Finally I tried a hail mary with Soft-15khz build 52, running it in both native Windows 10 mode and under Windows XP SP3 compatibility mode. I would boot up but all the Adapters were greyed out and unselectable along with all the controls at the bottom.
So, I am at my wits end with this and I would really appreciate some assistance because all my Google Fu is failing me. I don't know if there is something I am missing or configuring improperly or what. If you need additional info or screenshots, just let me know. I've tried to be as thorough as possible. If it is simply impossible with this set up, is there an adapter box that I can use? There is the aforementioned VGA port and 2 DisplayPorts. Additionally, if the solution is just to get a whole new PC (I hope not) can someone recommend a small form factor office PC that accepts video carts that can fit inside of a Sega Blast City? (I'm trying to use prebuilt office PCs because the most taxing software I want to run is on the level of the Dreamcast (NAOMI board stuff) and I would like to keep the PC build on the cheaper side as I played maybe a little too much for the Blast City and I'm a bit strapped for cash at the moment)
I appreciate any assistance and thank you in advance!!!!

[buttersoft]

That's one heck of a wall of text, lol.

I can generate the modes and install them just fine using the Nanao MS-2931 preset but I haven't been able to set the EDID. As such, even though I put Windows in 640x480, the J-PAC only lights the Sync In LED, not the Sync OK with the jumper just set to 31khz.

Err, i would guess the EDID shouldn't be affecting things in the way you describe there. Probably not relevant at the moment, anyway.

I suggest starting simple. Use VMM to remove all other video modes and install a single 640x480 mode. Try 480p, and if that isn't happy, try 480i and set your jumpers on the jpac and the MS-2931 chassis. Go into ArcadeOSD and make sure the mode looks ok, then try getting a picture on the CRT.

How are you getting from the Jpac to the MS-2931? Using the Jamma edge? If you can think of a way to bypass the Jpac, i'd certainly try it.