I'm not making any suggestions about the right to protest, as you have pointed out we have both taken part in marches/protests before, and its something in the UK which is a valid freedom and long may it last.
I happen to think those planning this protest got it wrong, I suspect with a large percentage of the British public, who until now have not really bothered about what is happening in the middle east, would have responded better (i.e. took notice of what is happening) if the protest leaders had said we will suspend the protest for this weekend, then continue thereafter. The publicity for the protesters cause would have been enhanced , because of the decision and thereby would have shot Braverman's fox.
The majority of the press/news vendors will ensure the public are tuning in for the wrong reasons tomorrow and God forbid if anything kicks off, then the next protest will become the 'replay' and the protesters will effectively find themselves protesting in an 'echo chamber'.
I sorry, but I don't agree that there is a relationship/synergy between a 'protest' and a 'remembrance' activity.