What Class D amps will drive a 2 ohm load

it does not double the power when halving the impedance - but it is apparently stable at 2 ohm

No it’s "not bad" for a class-D, nowhere near doubling still, at least it goes up as the impedance goes down, too many either don’t go up at all at 2ohms or go backwards. "Could" be ok for the OP’s speakers if it's to be believed, and "may" get the best out of the low impedance bass they have.
600 Watts at 8 Ohms
800 Watts at 4 Ohms
1400 Watts at 2 Ohms

It will be interesting to see with independent tests if they give it to someone like Stereophile, if they have "underquoted the 8ohm and 4ohm" to make the 2ohm look as good as it is. As many manufacturers are doing that now, that you can see that on Stereophiles bench tests, it one way of making the amp look to be doubling, and it’s wrong (lying) and should be stamped out.

Sorry - the specs above are for stereo single amp - the power is considerably more in mono block configuration

If these are bridged stereo’s into mono’s? (probably as they give no specs) if so they won’t even do as good as the stereo amp in doubling down.

Cheers George

I have driven my 1 ohm Scintilla's with the NC400 mono blocks from hypex.I use them sometimes in the summer months when it gets to warm for my Krell KRS100 mono blocks consuming 700watts each.

Link: https://www.diyclassd.com/product/nc400/11

Theta Digital Prometheus  -

8 ohm - 250 W
4 ohm - 500 W
2 ohm - 850 W  (measured by Stereophile at 980 W)

I have driven my 1 ohm Scintilla’s with the NC400 mono blocks from hypex.I use them sometimes in the summer months when it gets to warm for my Krell KRS100 mono blocks

My friend also has the Scintilla’s, what a great speaker when driven right.
With this
https://ibb.co/mSV04BP
https://ibb.co/m6LhhPc

1st post, bet you can’t wait for winter, otherwise you wouldn’t still own the Krells. It must be because they sound and drive the Apogee’s better by quite a margin, otherwise you would get rid of them?
Also there are cooler running Krells, that would sound almost as good as the 100 mono’s, and still blow away the NC’s on these great speakers..

Cheers George