OP, excellent idea for a thread! Hopefully I'll have some info in the future to contribute. As a suggestion, perhaps we can have a sticky at the top of this forum, listing all known live P/FLO8 MTTs.
APAT WCOAP is my go to live PLO8 tournament. They run it annually. It's only £56 to buy in and has no guarantee but you don't get m/any other chances to play PLO8 in the UK certainly.