I appreciate the input so far guys. Still weighing all options.
Here's what I'm trying to do.
Just a little jumper from one cab to the other when they're stacked.
The combo SpeakOn/¼" jacks are out of the picture, won't work for what I plan. It's a 2 pole plug, and the signal I want on it will be from connections 3&4 from a 4 pole plug. And, from the description, a 4 pole plug will fit in it. On a system wired with subs on the first pair, it could cause trouble if anything other than a jumper got plugged in there. So, that option is out unless I fill in the outer ring with resin and effectively disable the SpeakOn option, making it a ¼" plug only... which is an option and would be fine with me.
Just using standard 4 pole SpeakOn's is an option. It does keep continuity in the wiring scheme and wouldn't be too much trouble to create a jumper solution if I misplaced the actual jumper made for the purpose. I'd want to have 90º ends on the jumper and might have to add extra slack in the wire to allow the connector room to turn when inserting and removing it. Obviously, would have the top of the jack toward the outside of the cab.
I'll have to let some of those options roll around in my mind a bit. I'm still leaning toward the ¼" plug option and interested in at least identifying a workable jack for the purpose. So, please keep the recommendations coming guys.