I will possibly end up doing this on my Friday SFO-CLE flight. If the RPU doesn't clear at T24 (it won't) and IF they offer me the TOD I will buy up rather than continue to roll the dice for the chance the RPU will clear on the redeye. FWIW I will keep an eye on the RPU to make sure it is returned but quite honestly not sure why, they seem pretty worthless.
I have a another SFO-CLE turn around next month that I bought up to W with hope that at least that will clear. This Friday's flight I didn't buy up to W, exact class of ticket it is I don't know off hand.
Also still standing on RPUs placed months ago on two SFO-BOS flights for later next week and next month... not holding my breath on those and also did NOT buy up on those.