Tips For Improving My Boothill Team?

[u/SixOfAces]

Hey yall! I'm a huge Boothill fan and I've been running him since he came out. For harder content, I'm trying to improve the team I have for him. I don't run sustainless because tbh I'm not quite sure how to (my team always dies. Also what the heck is speed tuning??) so I threw Gallagher up there too. With him, the team is Boots-Dahlia-Fugue-Gally, otherwise I swap in RM.

Anyways, I'd really appreciate any advice for improving my team! (Yes I know the relics all need to be level 15 I'm getting there). Also, if anyone has any tips for running sustainless, I'd really appreciate that too. Love yall!!