BFI Blu-ray has better detail. Severin 4K Blu-ray has HDR but poor encode.

BFI Blu-ray renders grain structure better than Severin 4K Blu-ray’s disappointing encode, although Severin does feature an HDR grading with Dolby Vision. Furthermore, Severin’s soundtrack is worse due to the noise reduction applied.

Severin 4K Blu-ray has very good extras that are more relevant to the film

Theatrical: Some of the International Paramount BDs

Director's Cut: US WB or International Paramount Blu-ray?
Ultimate Cut: US WB or International Paramount 4K Blu-ray?

Theatrical: Some of the International Paramount BDs

Director's Cut: US WB or International Paramount Blu-ray?
Ultimate Cut: US WB or International Paramount 4K Blu-ray? (Paramount 4K Blu-ray has Dolby Vision but different colors compared to the WB)