The person IS eligible for Advance Parole, USCIS will grant it, problem being that if you depart with it you're not getting back in because you self removed.

Matter of Arrabally only pertains to the 3 and 10 year bans, it does not touch removal orders. Unless of course you want to do it and then be the precedent decision - good or bad. Unlikely that the BIA would side with you since it really undermines their own power of issuing removal orders if it gives USCIS the ability to essentially void them.

I talked to a lawyer before and basically there's nothing you can do against a removal order unless you have some method of fixing your status. ICE will simply not agree to reopening proceedings for the hell of it or solely because of AP.

So what does it look like for EWI with removal order?
You marry a US citizen. The citizen spouse files I-130 for you.
You seek reopening of proceedings since you want to try the hardship waiver or advance parole route (I am not sure if AP route is a valid argument, but considering that you can put down a whole list of arguments and court might agree or deny each of them individually then you can always put it down).
ICE will probably agree.
Immigration judge vacates previous order and reopens your proceedings.
You seek administrative closure to do the hardship waiver or AP.
Administrative closure will likely be granted.
You travel out of the country on AP and return.
Now you're an arriving alien, you can adjust status despite being in removal proceedings, however you have no right to review before a judge if your AOS is denied.
You file AOS packet with USCIS. (Note: AOS of arriving aliens is a something your typical drone worker might not know about, in case of which you might have your lawyer go with you and basically explain everything).
If there's another court session in your case you ask for a continuance since USCIS is reviewing your AOS due to them having the jurisdiction in AOS of arriving aliens.
USCIS will most likely give you a stokes interview.
If your AOS is approved then you and/or USCIS seeks to terminate the proceedings since now you're an LPR.

If your AOS is denied then you are fucked. You can try refiling with USCIS but it's questionable how well it'll work.
You might try the provisional waiver then, but considering that you already tricked them once to try AP they will likely deny that motion. In this case your only hope is to seek voluntary departure and then try the I-601 waiver.