Hey!
So I don't like to spend valuable dark sky tme on focusing routine, so setting filter position relative to a focusing filter seems like a great idea!
But setting the focuser position relative to a filter takes some time, especially if the scope is cooling down still. But even with a cooled scope, using this relative filter position method, the result often is inconsistent and sometimes it's just off, foe me at least (with a moderate f/5.3 system).

Would be nice to have a "calibrate filter focus position' routine, that for example focuses x times through all the filters and averages the results. In that way as sometimes users change or replace filters, just select which filters ons wishes to calibrate, relative to which focusing filter, and presto, off to the races.
In general, I think it could be an idea to have a 'system calibration' tab, where for instance darks, flats, polar align, guiding calibration, focuser calibration, and all such could live.
These aren't needed during operation and would clean up a few tabs perhaps?
Ok, I'm drifting off here... will post maybe later a concept w/ sketch.

What are your experiences on focusing relative to a 'focusing' filter?