As I know you like to questions things I will be very thorough. You were banned for "spamming". Spam can be defined as irrelevant, unsolicited or repetitive messages. After being warned several times you posted the following message.
"abcdefghijklmnopqrstuvwxy" can be defined as unsolicited, a word which here means "not requested or invited".
Aforementioned message can also be described as irrelevant. Irrelevant means "something that doesn't apply, or is not related to the subject". The alphabet is not related to towny, Minecraft, nor was it being discussed at the time.
Finally, this message is indeed repetitive as I can recall asking in the past if perhaps you needed someone to verify that you still knew your ABC's.
While it was installed to help combat lag, I feel the stacking plugin has increased the lag on the server. Even with very few people online, the server tends to get laggy. Where it wasn't before. The lag also seems to spike around when it makes its announcements. I do imagine deleting a bunch of stuff would put a strain on the server.
Another problem I have is it deletes item stacks off the ground. The first problem is that makes the /trash command useless to buy from the perks shop. Why waste money when you just need to throw your trash on the floor to delete it. The second reason is if you have the unfortunate luck to die too close to an item wipe are likely to lose everything you had, even if you could have gotten back to them.
I understand this point may no longer be valid as you have mentioned in the discord unstacking friendly mobs but it also makes farming more difficult. For example, It stacks my baby turtles and they only drop one scute per stack.