I got 2 different rainchecks at 2 different TRUs last TF sale and it was not an issue.
I got 1 store to honor a different store's raincheck here without issue when I found the Seekers 2-pack. The only problem was she took my paper which had 2 rainchecks on it instead of crossing it out and giving it back to me (I lost an Exhaust raincheck).
I got 1 store here to honor the raincheck when I bought Sky Lynx online. Brought in the email showing how I paid and the shipping invoice paper. Done in less than 1 minute.
Methinks that it's the unknowledgeable workers in those problem TRUs that are the problem as it is clearly working fine at others stores like the ones here.
I had no issue using any Dare Cookie coupon on any sale item. Online sale I added the $5 off without issue. In-Store they just scan and go as long as it is above $15.