If you are only going to visit a few objects per imaging session, then a par focal ring and eyepiece combo is a great idea, I used to use that technique with my Meade LPI using a Meade 20mm Plossl. When I switched to the DMK, I found that I needed an extension to my 1 ¼ inch eyepiece in order to fit the par focal ring on the 1 ¼ tube.
Also, when flitting between several targets in an evening’s session, such as double stars, I find it more convenient to use the 9x50 finder which always puts the target on the DMK CCD after a GoTo slew.
I would probably find it inconvenient to manually move the ‘scope to a new target and swap between eyepiece and CCD each time to centre the target? I must be lazy,
!
Cheers
Dennis