As the title suggests, using those 3 mods together, but the functionality isn't as I'd have hoped.

The tree chopping is inconsistent, but by tweaking the setting, I can get it to work, but then it cancels the other two mods out.

I can either break the tree and have it fall while it also drops block fragments, or I can chop the tree, but then it only does block fragments for the one log, and it has no falling animation.

I though Panda's and HT's had compatibility, but it seams I can only use one or the other, either by crouching, or now.

Could this be fixed?

Hey, thanks for reporting. The compatibility is handled by Panda's Falling Trees, see PandaMods-Dev/Pandas-Falling-Trees#37. I don't actually know how it works. Could you check with them first?

Hello @ZombieGuildford, Compatibility with TreeChop and Panda's Falling Trees has just been released today, At the moment you can only get the latest version of Panda's Falling Trees on CurseForge and Github but Modrinth will be released at a later time.
Also Panda's Falling Trees is semi incompatible with Physics mods because it spawns the broken parts of the blocks when the tree falls, this is can have changed in the latest release because i have made some improvements to the way the blocks are handled.