I guess I'll take a crack at it.
-First things first I think it would be a good idea to either increase league hours by a small margin(perhaps an hour would be the best), or start earlier.
-I noticed during the later stages of the season a lack of staff. In particular I noticed one day that league wasn't even expected to run because of the lack of it. I believe that day only Washman and one other was around(may have been one more on but you get the point). Granted, it's understandable. People have lives to attend to. School, work, etc. Which brings me to my suggestion. More staff. I think branching out and getting more people involved will help availability. Reborn league had a back up host for every line in case the main host couldn't do their job for the day for whatever reason be it an emergency or what have you. It's something worth talking about at the very least.
-This happened very few times, and I only witnessed it firsthand once. But dc's were being treated as losses by some of the leaders. For the sake of anonymity I won't give names. However, I think that doing such a thing cheats the challenger out of a battle. And I mean, really? It's out of their control. At the same time I realize you can't just hold up the line because someone keeps disconnecting. So perhaps implement a 3 strikes sort of rule for that situation. Again this is only from what I noticed, and I'm not perfect and probably just missed something. Even still, being prepared for such cases is nice and I think 3 strikes is a good number for such events.
-Personally, I have no gripes with the way move changes and such go. I'm fine with the way things are in that regard.
-As for legendaries. If you chose to allow some, perhaps instead of tiering do it by BST.
-I can tell you firsthand that you will regret allowing Retry Tokens if you choose to do so. Being an abuser of them myself, as well as being part of the Reborn league staff. Trust me, it's not an item you want to just hand out. Maybe as a RARE prize in a tour. Extreme emphasis on rare.
I don't have much else to say other than Redemption ran well for its first season. It has some adjustments to be made, of course. It was a very successful introduction to something that could very well last a long while.
One final thing, of course. My reason for losing interest was mainly due to having to battle on my phone 2 of 3 days(sometimes even the full 3) and because I quickly lost interest in Pokemon. Nothing to do with Redemption at all. In fact it was because it was as fun as it was that I even took part as long as I did. I just got tired of playing Pokemon.