I guess this really boils down to whether you feel comfortable riding a "damaged" tyre, but when does the time come to cut your losses and reach for your wallet?
The questions is; should this tyre get binned? Sorry, no image, but it has a semi-circular cut that can be peeled back to reveal the thread underneath. It is not bulging (at 115psi) so structurally it's holding, but is it worth the risk?
I'm getting through too many tyres, but am not keen on the trial & error method (70kph descent ) of striking the right balance between replacing or not.
Don't like wasting money but, then, I don't like hospital either.....