Battery Holder/Case for Protected 18650 Batteries in Series

Has anyone found a good holder/case for protected 18650 batteries? I ordered one of these, but it’s very tight with my protected 18650s. I’ve seen a lot of different holders, but most of the comments say they are only good for unprotected cells.

Ultimately, I’m looking to connect 4-6 protected batteries (haven’t decided yet) in series. I’m mostly interested in a flat arrangement so I can mount it against something. If you’ve found a good holder for protected 18650s, even if it’s just for a single cell, send me a link.