You can get huge fungus with bonemeal in Bedrock
I was making a fungus wood farm when I stumbled on this. Checking the wiki, it says there that "If a huge fungus is grown with bone meal, its stem will always be the thin 1×1 variant." I fixed the wiki but also wanted to share this to y'all. From my testing, in a sample of 100 trees, there is a 6% chance of the stem being the huge variant.