Hey Daran,
There’s tons of posts and theories out there and I agree, it’s as clear as mud it seems. One bit that’s important is that sometimes, specific events (like Simulator or Gauntlet) throw the rules out the window on purpose, so something to keep in mind, but here’s my general thoughts/theories on this (based on what I’ve experienced and read here on the forums).
The below is just on PVE, I don’t think this applies to PVP as that is based on something different (MMR).
At the start of a Sub, the enemy levels are set based on your roster level (via some magical D3 formula). Once you start playing, then personal and community scaling can kick in. If you end up destroying a node and crushing a sub, your personal scaling can/will make those node difficulty increase (partly or mainly) due to the notions you made earlier about not losing health. I believe node difficulty will typically increase regardless, but you can accelerate that by doing “too well” on a node. Personal experience tells me that “Trivial” nodes never scale up and are pretty much free points. However, if the community is also destroying nodes, then you can come back to see even higher levels the next time you go through.
I observed this in Simulator Hard on that Jugs/Colossus/Bagman node, I did it the first time and barely got out alive and decided to not go back. I’d check on it every now and then only to see it go from a barely manageable 220 to “no freaking way in hell” 395 without me ever touching it. Which led me to believe it was all due to Community Scaling and made me think “How the fuck are people clearing this??”, I then discovered the Magstique Combo on the forums and tried it out and realized how relatively easy it was to win with that team and I then started adding easy victories to the community scaling too. This is an extreme example of Community Scaling, but it does unfortunately handicap those who aren’t able to replicate the same strategy.
Rarely, I think the reverse also is true and if the community as a whole is struggling in a sub, then difficulty also goes down. Just doesn’t happen often early on and I think if it happens later, it’s because lots of folks have stopped grinding at that point.
Going back to your roster and maxed characters, I would theorize that having more maxed characters can be a detriment when the featured buffed characters end up being one of those maxed characters. You do not have any maxed 4*, so when a 166 gets megabuffed and has 90 levels added, it now affects the starting levels of the PVE subs. Those that have maxed 4* probably aren’t seeing a difference when it comes to buffed 3*, but for someone like yourself who has not leveled any 4* can actually see nodes seemingly increase to very difficult levels arbitrarily simply based on a featured character messing with your starting levels. You’re then subject to personal and community scaling as before, but you have a much more difficult start. This goes away if you max a 4* of course as that will be the basis for your starting levels for a PVE, but you are also now starting off with higher levels than with a 166 roster.
One way they can combat this is to simply buff characters to your top level character only (or add the requisite mini or mega buff, whichever doesn’t cause them to go past your max character). At least this way, you still get the benefit if you haven’t leveled that character, but they also don’t completely mess with the starting levels.
When Sentry was buffed, I definitely had a hard time since I do have him maxed and I don’t have a character above 192, it wasn’t terrible, but I could feel it. I’m also not looking forward to seeing Hood getting the big buff in the next PVE for the same reason, lol.
Anyway, those are my thoughts on the matter, may or may not be correct, just my theory so far.