Yeah, I had a bit of an experiment about this earlier.
Noticed the max_pages commit when it was pushed to mergerfs and was searching about how to use it in rclone. Figured that it was something that needed to be supported in the fuse backend used by rclone so went looking for it in the corresponding library.
Saw that bazil/fuse was not being maintained so again went looking through the alternative libraries available for rclone. Found the go-fuse library and created this issue there. Unfortunately, haven't been able to make progress there since I am not sure what flag to pass and the author seems stumped too.
Perhaps @trapexit could provide some help here?