Hi @Lquiroz and @cdfleischmann
Please can you let me know if you were successful?
Im facing the same issue where J20 doesn't seem to be working while the rest are working.
I will give build 449.01.hex a try, but not sure it would work based on your experience.
If you can share the code changes you have done to get this working or even the hex file that I can upload into my Tinyg it would be really helpful.
Looking forward to your response.