When lag b’omer falls on Sunday we are allowed to shave on Friday. Since it is lekovod shabbos, do we have to wait till chatzos to show that it is lekovos shabbos or can we shave even before chatzos?
I personally wait as late as possible (every Erev Shabbos during Sefirah) but I don’t have any Makor that says that you have to or even advises it. In fact, I’ve been recently thinking that earlier might be better because we often say that doing work too close to Shabbos and being rushed late on Erev Shabbos is itself a lack of Kavod Shabbos.
For those who wish to take a haircut on Friday, as far as I know it is allowed all day long.
However, re shaving, you are assuming one is not allowed to shave in Sefirah. If one is clean-shaven, it seems quite obvious that one should be able to shave daily (or close to daily). See Nefesh HaRav by Rav Herschel Schachter.