There's no hurry, but please add arches when ready to stabilise.
(I wouldn't feel particularly pressured by the security bug, either. I appreciate people hurrying up when they can, but in this case, it's an API change, so it's not like it's going to make much difference until consumers are ready anyway.)
Regardless, revdeps must be ready before we can stabilise Qt 5.15 and this is the best way to keep track of the effort, considering the overall lack of stabilisation morale.
x86 stable. Closing.