Lunt 100 with Denk Binoviewer Eyepiece Question

I'm using a Lunt 100 solar scope with the OCS and binoviewer provided by Denkmeier optical. The OCS and binoviewer power switch were designed for the Lunt 60 which has a FL of 500mm. With the Lunt 100's FL of 800mm I get too much magnification to make good use of the power switch on the binoviewer using 21mm or 25mm eyepieces. I am going to look for eyepieces with a longer focal length. Any comments by participants who have dealt with this are appreciated.

Thanks, Tony