I put to you that life is too short to miss out on the smoother shaves found after the second use.
And the potential improvements in technique that come from even relatively short long-hauls (by Excalibur standards)...
I don't imagine many will be able to take a blade to 20+ and tell me they haven't learned anything at all from the experience...
Having said that - I can respect people who have gotten 20+ from a blade or two and decided they prefer shave 1/2/3 and don't want to go the extra mile regularly... I just think anyone that hasn't tried it is missing out.
(And I say 20 only because that's as far as I've personally gone... Intending to go further in future for sure - but perhaps not this month!!)