I've been using plastic reels for 40 years, both 35 and 120, and have had no serious problems. Absolutely no development problems. Occasionally I will have trouble getting a roll onto the reel. About 15 years ago, it took about an hour to get a 120 roll on. I think it finally depended on me cursing a blue streak. But it developed fine. When I do have trouble getting a roll onto a reel, I put the roll completely out and start again; I don't force anything.
And I have a few reels that apparently aren't stable enough for 120 film, so I only use those for 35. I never had a reason to use SS, and I still don't.
For those who love SS, I have a few reels available for sale. Selling for a friend that gave up on film.