I've tried 660 dawgs, big ass 4-point Pro-Saftey dawgs too on the 261 & both times returned back to the 361 dual dawg/roller catcher kit. I agree with you the design is far from perfect but...I found big 660 style dawgz will 'bog' or stall the saw to easy. Its a physics/mathmatical thing where the fulcrum point when moved forward changes the leverage so you need to be much lighter on the hands when setting dawgs and lifting rear handle. But if they work well...they work well. The single factory 261 (now nasty pressed style) dawg is pretty useless in thick bark here. I'm all ears if there is a better option than the 361/2 kit. Like to know whatcha think after a few good cutting sessions.
EDIT: I noticed you brought the mount holes forward which would make them less likely to bog saw....might have to give that a go!