This seems to be a resurrected style that doesn't really have any modern guidelines. I have read that back in the day tavern owners might mix mead and ale as it was being served.
I have mostly run into Braggot in the context of mead rather than beer and so had the impression that it is very honey forward. I personally think of the percentages of honey vs malt in percentage of fermentables rather than in pounds because of the vast difference in weight vs sugar.
I have a Braggot on tap now that is about 50% honey and 50% malt as fermentables. It is 6% abv which I don't think is typical, Ithink highr abv is more common, so I think of it as a "Session Braggot" or "Hydrobraggot". At 50% fermentables from honey and the rest something like 44% munich and 6% 50-60 crystal it is very honey forward but there is enough malt presence that it drinks like a beer.
I don't think you need 50% fermentables from honey to call it a braggot but in my mind it needs to be honey forward as opposed to a beer with honey notes. I am guessing that would usually be north of 30% but would depend a little bit on the grain bill and assertiveness of the honey used.