lr-fba-next (Neo-Geo) freezing/crashing my Retropie after editing config.txt

[ScOULaris]

So I've always had the following lines in my config.txt for modest overclocking with few issues on my Pi 2+:

arm_freq=1000
over_voltage=2

I recently stumbled upon this wiki page and learned that there were a few more parameters that I could set for overclocking RAM and setting the CPU/GPU core speeds as well. So I basically added all of this to my config.txt:

arm_freq=1000
gpu_freq=500
core_freq=500
sdram_freq=500
sdram_schmoo=0x02000020
over_voltage=2
sdram_over_voltage=2

After doing that and rebooting, everything seemed fine until I started playing Neo-Geo ROMs the next morning. I noticed that after a minute or two of playing any Neo-Geo game on the lr-fba-next core (Retropie 3.8.1) they would either completely lock-up my Retropie or suddenly exit back out to the ROM list screen on their own.

Suspecting that my recent config.txt changes had something to do with it, I first removed these lines:

sdram_freq=500
sdram_schmoo=0x02000020
sdram_over_voltage=2

So now I just had the arm_freq, core_freq, gpu_freq, and over_voltage parameters still in there and rebooted.

Tested some Neo-Geo games again and had the same problem. Freezing and locking up my entire Retropie within a minute or two of running any ROM. I tested some other emulators like NES/SNES and I didn't have this problem crop up after several minutes of play.

My next step will be to just return to my original settings with only arm_freq and over_voltage, but I won't be able to try that until I get home from work later.

Does anyone know why this might be happening, specifically with Neo-Geo ROMs all of a sudden? Since they are hard locks that necessitate a reboot I'm thinking that they are definitely overclocking-related, but I don't see why such modest settings like core_freq=500 and gpu_freq=500 would cause this to happen.