I used to do that. Now I ride up between the lines of stopped cars to the head of the line. It is legal to do so in my State.
Then I continue to monitor my mirrors, keep the bike in 1st gear ready to move if there's a pileup behind me. I'm also watching cross-traffic in case I need to get out of the way.
If I'm the first vehicle to stop, I watch my mirrors and cross-traffic more intently, with the bike in 1st gear and ready to take off if the cars behind are not stopping.
To your point of tapping the rear brake or front lever to flash the taillight to wake up those following, I do that too. I'm not sure why it might be considered difficult to do by some...