I would stay away from BTRFS, atleast if you want to use Timeshift and restore your snapshots… You need a diplom to get your system from working again, while on EXT4 is so awesome user friendly.
You can also easily destroy your own BTRFS Snapshots with timeshift, since BTRFS allows booting right into this snapshots and it has no write protection… for me this sounds not reliable.
At least this is just my noob opinion after i saw few month ago a painfull long help topic in this forum about BRTFS Snapshot restoring… i have absolute no idea who wants this? Maybe because BTRFS is so much better than EXT4? I have no idea.
Only 106 Pages long till the Problem could be solved… Ultimate user experience i would say 