I've been reading back through old threads on FOG and thought this old suggestion a good one that deserved a 2nd look.
Now that the Domino 700 is out, I believe a glue bottle with a series of different caps, that are sized for the various sized tenons, along with the reach to get to the bottom of the full depth of the 700's plunge, would be very helpful. Change caps based on the size tenon you are using and quickly get an even coat of glue along the walls of the mortise for a solid glue joint. This could allow people to work faster and produce consistently reliable joints. Compare the time to push the glue bottle into the joint and squeeze as you pull it out vs. having to play around with a disposable brush trying to spread glue evenly along the walls of the mortise. Festool is all about making professionals more productive so, IMHO, this would seem to be a "no brainer".
I'm in the market for a Domino and would definitely be interested in purchasing a glue bottle like this as an accessory.
My $.02
Jay