PB ... I don't want to appear insensitive but, it needs to be said, you don't have a 'comfort bike'. I'm not actually certain that at your weight you can get away with using less than the max pressure in a 25 or 28. Don't fall for the claptrap of the tubeless contingent. 'Comfort' and 'racebike' are mutually exclusive concepts. It shouldn't be injurious, or actually painful, but you are not going to discern much if any difference in comfort between the OEM 25mm and 28mm, as you already discovered. 30mm isn't going to cross some threshold either. HTFU and ride that beautiful bike of yours.