When choosing a UK casino with many high RTP slots, start by checking the game...

https://meet-wiki.win/index.php/Why_Do_Bigger_Game_Libraries_Matter_for_RTP_Hunters%3F

When choosing a UK casino with many high RTP slots, start by checking the game library size and variety of software providers. RTP is a theoretical number, so look for casinos that offer filters by provider and category to easily find slots that suit you