The mask thing is a mistake, although they should be mandatory with no exceptions as too many 'cant' wear a mask. So in that respect its pretty much optional already!
There's more "can't wear a mask" this year, than this time last year. Does little to slow their gaping or smoking though. And a load seem to be either headed to or coming from a pub. I've seen some who had no such trouble whilst the pubs were shut. But a card on a sunflower lanyard gets you out of wearing one.
I wouldn't say "no exceptions" but I would be in favour of proof to be carried and shown to public health officers on request.
A few issues,
What sort of evidence.
I've been asked for written proof, doctors letter, my blue badge. I don't drive so no blue badge. Doctors letter would cost £17.50 minimum, who pays?
I think a swollen mouth, with added blood, and "raspy breathing" should be proof enough.
Public Health Officer
Should they be allowed to ask if they themselves don't abide by the rules. We'd "jumped up" "Ambassadors", who the year before were there to help people within the town centre, suddenly given the power to ask people to comply with the regulations. They didn't have to as they "talking to people", handing out QR code sheets and signage to shops that were open along with checking that they were sticking to the rules.
It's safe to say that I had my fill of council badge waving last. Waving to show that they were council employee's and didn't have to do what everyone else did.
Something you can both try, paper mask.
Open your mouth and draw as much air in as possible, as quick as possible. Where does the mask end up?
Bike pump, rapidly pump up an innertube. What does the pump feel like when you're done. Now imagine six litres in the time it took you to do the first two strokes of the pump, and the effect of that on the throat.
I'm aware that I've said I use a full face mask, but there's times when that hasn't been possible. I'll comply as best I can, but I know that there'll be times that's not possible, nor practical.
Come back when you can give a workaround the above.