The guys from hardkernel are working since last nov '19 on an update to linux 5.4, do look really promising.
forum: https://forum.odroid.com/viewtopic.php?f=184&t=36947
kernel sources: https://github.com/hardkernel/linux/tree/odroid-5.4.y
do support the following boards: XU3[-lite], XU4, MC1, HC1, HC2
Issue I can find by digging the forum posts so far:
$this->bbcode_second_pass_quote('', '
')- r/w to some µsd-cards is slow (maybe already fixed with latest commits?)