The tyre is losing pressure slowly over a few days, made a note of it to get it sorted soon, I’ve seen the nail, looks repairable to me..
As to run flats I think it’s a great idea, I seem to pick up punctures quite often, (hence my tyre repair kits previous years) this will be the second in this Volvo in 16months of having it..
Had run flats on my Daughters cars, it eased my mind, so got to be a good thing..