An option to hide [deleted] messages completely (a la classic Discord) would be good for organizational purposes and to keep announcement channels looking clean. I am aware that it clears the notifier on client restart but the less I have to do that the better.

This is not something I can easily implement on the Discord side right now, because the scrolling log implementation relies on the message anchor points remaining in existence during certain operations to avoid having the scrolling position reset. I had the foresight to not make this same mistake in the Slack implementation, but going back and fixing this in Discord is not something that I can justify allocating time for right now.