@Jonathan_P yep, photoflex softboxes, XS S or M all work. Use their plastic speed ring, rivet (or screw) a steel plate (the kind with 2 or four holes drilled already) to the plastic speed ring, then screw the 312 light in with a seperate screw and use the black screw fasteners that come with the 312 light to tighten in place.
Probably doesn't make sense but is very easy. Will snap a photo and post when I got it setup and am shooting with it again on Wednesday. Apologies for delayed response -- on vacation for two weeks.
Screen grabs of the first test with this setup (sorry for cross posting but figure better than referencing the thread where these are already posted, only to end up reposting in the end).
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