Identifying Infrequently repeating keys: PS/2 Library

Need help trying to isolate an issue. Built a bluetooth ps/2 based keyboard with
the arduino uno and bluefruit ez-key. It mostly works have added control and alt functionalty

Modified the ps/2 library found at
My modifications and an example sketch can be found
here- GitHub - PaulBeaudet/neoboard: PS/2 Keyboard to Bluefruit convertion: Planned type assitence features

Whilst debugging I have noticed infrequent fits of repeating keys. Trying to figure
out why this is happening. My current hypothosis is its either the bluefruit choking on bits,
or the interupt is affecting the key report expectations of the bluefruit.

I know for sure that if the bluefruit misses the "breaking" keyreport ( 0xFD + eight zero value bytes)
then keys will repeat.

I want to test this by seeing the serial output in hex. Right now I just get a bunch on question marks
with the arduino serial monitor.
Suggestions in Linux? I've tried a few terminal programs, but the explanation on how to use
them was lacking.

Maybe there is a differnt way to approach troubleshooting this issue?

Found a program called "coolterm" here-
Works good in Mint.

Seeing the output in hex I was able to see repeat key pressed without hex output.
Also no interuptions in the "break" communication as I suspected. From that I have
To further suspect the bluefruit of choking on bits. Just have to find out what
that means. I have a second one I can test with, but I'll have to take it out
of another project.

The bluefruit related stuff is probably better to softball in the adafruit forums.
However if anyone has other ideas or interest I'm all ears.