My current plane has about 1.6G at FL450, so your point is? Probably something about larger planes.
My point is that with 1.6g available, you have
plenty of potential to follow the RA.
I might not have expressed it well? To clarify, my point is your priorities are somewhat adrift if you have climbed to a FL where your performance would be so limited that following an RA gives you any concern. You would surely also be considering turbulence, windshear (it terms of W/V altering quickly), engine failure etc. all of which require some tolerance to IAS/M altering somewhat.
And the absolute (rather than current) Max Ceiling will often have pressurisation / fatigue as a factor, which are not applicable here.
Summary: At FL390 in a 320 series Airbus, I am much happier explaining to my Flt Mgr why I went to FL395 following an RA, than ignoring the RA and all the consequences of that
NoD