Thorns can definitely be some trouble and it would explain why you had at least one bird showing signs of pain. Mine thankfully haven't wandered into the bramble yet (we have a ton of thorny blackberry).
I should've worded it better. I've never had a case so severe that it required cutting into the tissue but I do think the ones with more noticeable scabs should be soaked and the scabs removed. And yes I would do that with the small scabs as well. They may not necessarily worsen but I've never seen them go away without treatment either, which is why I find it best to treat it when I can.