You’d be ok w/ the sinkpad brand mtg2 pcb and 5A or so at the emitter, but you have to make sure there is very good contact between pill and emitter. If there is poor contact, the dome will bubble at the emitter. If there is (minimally) adequate contact, a light meter will reveal a big sag in output in the first 30 seconds…
One other note about that driver - personally, I wouldn’t consider using it unless it is potted.
anyway, pptk was right, 4-5A is very doable, and w/ great care, so is more
Who has pcb, better, copper pcb for the MT-G2?
i’m not aware of a copper one, but sinkpad makes aluminum mtg pcbs. maybe someday they’ll get popular enough for a custom run of copper pcbs…
Or, if the pill is already made you can send it to me and make another like dthrckt suggests. 
Sinkpad might even send you a couple alum versions as samples . . check MTG2 interest box if you haven’t asked for samples via their website yet.
You can also put copper under “Other”, but that will probably only be XML and XPG versions already available if you check those boxes, too.
Damn, wish I would have thought of that one.
1/8" copper plate...
Thanks guys for the input If I read this correctly there is no copper sinkpad available for this. Thanks for the suggestions on mounting it on a pillar but with all my electronic skills I would kill the led and I don’t really want to do that with $20.00. So its 5 amps max and lots off luck. Cheers.
Would an mtg2 fit on an xre board? Not got one to measure (xre), but looking on the cree data sheets it does look possible……and you might be able to get a copper sinkpad sample too!
I have a bare Cutter 20mm board and I'll have to desolder an XR-E from a 3-up board, but I can check that fairly quick.
How quick. I’ve got 10 minutes before I go to work? 
Hell, I don't even need to desolder the XR-E to see that it'll work, holding them next to each other is enough. The MT-G is of course wider, but the spacing of contact-center pad-contact is exactly the same. A little of the MT-G2 will hang off each side but that shouldn't hurt anything.
It will work, but sinkpad doesn’t make copper XR-E boards (or aluminum XR-E, last time I checked), and if you were going to use an aluminum pcb, you might as well use their MTG pcb, since like all their pcbs, the center pad has no dielectric layer.
Ooops I didn’t check to see if they did a copper pcb (or not)! Sorry folks
I would like to recommend you reconsider your decision to go aluminum star versed direct copper mount. You have build an amazing host that could take the MTG2 to new levels. The aluminum sinkpad will hobble the potential of the light. When you look at this very big emitter, you will see that it would be easy to direct mount on a copper pedestal and then direct solder wires to the emitter.
I second that, because I think you’re capable, but also for my own curiosity and the good of the forum
There’s a very easy way to reflow that mtg2 onto the pedestal - turn an aluminum ring w/ ID of the diagonal length of the MTG2 and OD that matches the ID of the pill recess. Set everything in place. heat it up. done.
If you want a potted 9A driver I’m happy to do it for you and I already have one ready to go - just tell me the dimension of the driver recess.
This makes it safer and longer lasting, so it is less risk if you use the same amps in.
and BRIGHTER :party:
I do have to warn you though, soldering wires to the LED is HARD once it's attached to a big chunk of copper.
I’ve done a couple xmls and I soldered the leads first
edit: and if you really want to be safe doing that, use a higher temp solder on the leads…