*@maxgerhardt which would my humble self
For general plans on that @ivankravets should be asked.
No. We already made progress on AVR debugging by adding avr-stub which works over serial (so actually easier than a dedicated adapter) and is known to work with your Arduino Mega. So you’re good to go.
Also we have simavr as a simulation tool.
There have been multiple attempts at Atmega32 debugging with avarice and avr-gdb and Debugging AVR / Arduino with ATMELICE / JTAGICE3 and avarice / avr-gdb but nothing fully working flawlessly as far as I’m seeing.
See above