@Targetron the answer to your question can vary quite a bit depending on the volume and process (push-all?). I can tell you how my team operates though. Allocate 34 hours to my backroom on a 2200 piece truck day with a pfresh truck and you will see no backstock, ELR's being worked, and a backroom that has been swept. Along with this, my team pulls all instocks batches and partners with the LOD to LOCU bottom departments to drive sales. Again, every store is different. If I read your post correctly, you are not a TL and it sounds like you are in the position many of my team members felt trapped in. Your TL needs to re-evaluate how they are using the backroom hours. If your TL is not a senior, they should be in the backroom doing everything a backroom team member does. On instocks days (assuming they are Backroom-Instocks) then their shift should be split 50-50. I have always lead by the belief that I will never ask someone to do something I will not. Therefore, you can bet I'll be right next to you back-stocking that towering paper pallet.
The Flow TL is responsible for all Challenge vehicles. My team considers filling a challenge tub a game and its been something that has drastically improved morale, and why shouldn't it? Challenge that is burned is an unnecessary step and extra work. It destroys efficiency. To them it is a way of challenging upwards and showing the Flow TL that audits and follow-ups need to be completed. If the challenge is not completely worked out by the time the Flow TL leaves, I take 2 backroom TM's (depending on the amount to be worked) and we race. First one done gets their name on the board, beat me three times I'll buy you a snack/drink on your break.