My solution, for what it's worth, is to change over to manual focus (if necessary) and use an "old-school" linear polariser.
My reasoning was this :-
I've got one, let's try it ... yippee it worked
'Old-style' polarisers are almost given away on eBay etc., so acquiring one (or more) in every size is a real possibility!
I've read "somewhere authoritative" that Pentax cameras don't actually need circular polarisers, due to the "different" way they operate, compared to other manufacturers.
Why would I want/need two filters the same size? Stack them and instant variable ND filter
As for wearing polarising sunglasses whilst using a DSLR ... non-starter. Both the optical viewfinder and the rear screen have built-in polarising filters, for various technical reasons (try watching a flat-screen TV with your sunglasses on)
Inevitably - YMMV