This is the Workshop Essentials Festool Domino Dual-Purpose Workpiece Support Jig.
Here's the thing. The Domino has transformed small-scale M&T joinery, but like every tool it has its limitations. Problems start to arise when the workpiece gets very narrow or very short. If it is narrow then there is not much surface area on which to register the machine. You can have it tilted over
or tilted back
and the narrower the workpiece gets, the greater the problem.
Also if the workpiece is very short, the clamp gets in the way.
What to do?
Well the first thing is to plan ahead. When I thickness my stock ready for dominoing, I need to make sure that I have another couple of bits machined on the same setting, and I screw them to the jig.
The distance apart is the width of the workpiece plus a bit of clearance, in this case the thickness of my steel rule.
So the workpiece sits in the jig, supported entirely on the bench and restrained by the blocks and the stop-block.
There is no clamping required, just drop them all in one after the other and domino away. The extra blocks give me a nice big area on which to register the machine. It's virtually impossible to tilt over, even with the narrowest of workpieces.
When it comes to cutting the mortice in the stile, the blocks are reset to keep the front edge flush with the front of the jig. The other end is supported by that auxilliary piece. Again, there is lots of support now.
I've yet to use it in anger, of course, but from this little test it appears to do everything I hoped it would.
For workpieces that are longer than the jig, I will have to remove the stop-block and clamp in the more trad way, but I might try experimenting with a pair of featherboards which will allow me to insert the workpiece from behind, but grip it when I push. We'll see.
Sincere apologies if you have been following this with interest only to to find that you need a Domino...