I just found this challenge yesterday and am giving it a try. I modified it a bit for personal preference.
One being each time I die, or fall off or out of my tree I have to sacrifice a sapling. Just like with the heart woos if I run put of saplings game over.
I also use random number generator. After X amount of days we have a rare day of peace. I switch to peaceful and I am allowed to venture from my tree and explore a bit of the surrounding area for one day. I have to be back in my heartwood base by sunrise the following day. Every minute I am not touching my tree after sunrise is minus one sapling.
If any part of my tree gets damaged minus 4 saplings and I can no longer use disconnected parts.
As an added bonus. I can only use wood from that one tree to craft. All other trees logs and wood are a no go. Not even for sticks or planks. It takes longer to build but I am enjoying it. I have a small tree fort built and the free day every so many regular days gives me a short break and allows me to gather resources I normally would not get as easily. I will be working on expanding my furst "roots" when my heartwood home is finished.