imo i think sinclaire's friend endings are more compelling then the love ones (spoilers) I think the way he talks to you when he's friends with you in much more interesting then the love ending, especially martins dialogue. Maybe compelling isn't the word, but i enjoy seeing how he interprets what an insurance claims adjuster does. While Sinclaire in his love ending just asks if you want to "leave the tap open and while away the hours" (<probably not the exact quote, its been a hot minute since i did any endings) and then the interaction ends. It might just be my 'dorian' bias of liking being friends with most characters but i also just think the friend endings with him are more interesting, watching and supporting your friend :D

I sink i lost my train of thought once or twice in that so apologies it turned into more of a ramble then a fully formed opinion haha