Sorry I had to run out for a minute, but your setup in the screenshot should work, I don’t think you will break the matrix. 
And what erWilly posted is definitely the way to go, pictures make things so much easier to explain, thanks for that erWilly. Things get complicated when using delay timers as every time the Draw Hud event fires, it would re-evaluate the same data without a gate (meaning it would create a new timer each time without a gate), so using gates will definitely be necessary to get the functionality you are looking for. Performance wise as well, the gate will make sure the different messages in your tree aren’t running unnecessarily.
For getting more than just one true/false, have a look into using a Switch statement, it is basically multiple Branch statements in one node that the blueprint would go through and test each case, and run only the ones that evaluate as true, that could be another way to go, but it can also be complicated to wrap your head around. Just keep it in mind if later you notice that you are using a lot of branch statements, as it could make it more readable.
Sorry I got a bit confused as to what you were wanting to achieve, but it looks you are on the right track now!