The coil doesn't actually "run out" of progestogen for a long time after the licensing time for HRT has passed - which is 4 years. I think I read somewhere that there is still progestogen ( or can be) after 10 years. Also it is licensed for contraception for 5 years. Therefore if it has only been in for 4.5 years it will almost certainly still be chucking out some progestogen. You will therefore almost certainly be having too much if you are taking Evorel conti as well or Evorel sequi ( when you are tkaing the conti patches).
One reason for the spotting could actually be due to excess progestogen - which can cause overthinning and ulceration, and spotting. It does depend where you are now in menopause, ie whether you are still ovulating at all in the background and producing some oestrogen as well as from the patch.
Yes too much progestogen could have an effect on all of that - not sure about skin but defo mood! However I would have thought you might have noticed the effects before now ie when you started the Evorel sequi ( or conti ) 2 years ago on top of the Mirena.
Also you have two different synthetic progestogens in your body - levonorgestrel from the Mirena and norethisterone fromn the Evorel so who knows how they are interacting with all your various receptors and hormones?!
If you were happy with the Mirena this would be the better option rather than the patches because as I said you won;t have to worry about progesterone for another 4 years. This should be your choice and either option should protect your uterus. You might prefer just to have a single patch and then not worry - buit you could still do the same with the mirena in - just have oestrogen only patches. I can't understand why you weren't given just Eovrel 50 rather than sequi/conti - but maybe even with the Mirena in your bleeds were heavy? However if all is healthy in your womb you shouldn't have heavy bleeds now....so either Mirena + oestrogen, or combi patch, should be fine.
Hurdity x