I wasn't having these panics. Catalina 10.15.5 on MBP 16", iiyama external monitor via DP, and MBP is closed.
I was having the problem where the MBP wouldn't wake up the external monitor. I'd have to plug/unplug it to get it to wake up, and then it would work. No regular crashes.
Yesterday I realised that SystemPreferences->EnergySaver->Turn Display off after setting was at 'Never'. I adjusted it to 30 minutes. Viola, I thought, the screen will wake up from a keyboard tap again.
After than it crashed every time it would sleep.
So, today I've tried the Do Not Disturb when screen locked setting above, as well as moving the 'Turn Display off after' setting back to 'Never'.
We'll see.
I don't know if a combination of those settings will help other people, but thought it worth mentioning.