I started a thread a few months ago with me doing some handstand work on my knuckles on a carpeted surface, asking for advice on whether it's safe (the Shaolin monks do it) and how I can build up to doing it on harder surfaces. Original video:
So, taking your advice, I slowly built up to harder surfaces by doing very spaced out knuckles sessions (maybe once per week) with low volume. Now, I am aware that this probably isn't ideal for my knuckles and fingers but I like to think the low volume and so far the lack of any sort of pain/discomfort would be good signs that I may be able type on a keyboard in 20 years time! 2 weeks ago:
Dangerous and potentially debilitating or not, I thought this was worth sharing with you guys!