Two ALS-XZs that I don't understand
Hey y'all. Ran into this puzzle on a daily solving app I use with some friends. It has a mode with no guardrails on the puzzle generation that locks you out of the puzzle if you make a single mistake of any kind, and it often puts out some real doozies that are just too far outside my abilities to finish within the hour or two I have a day to solve puzzles, and then the puzzle expires because the day rolls over. This was today's puzzle. I plugged it into yzf's solver and it showed these two moves that I don't really understand what it's showing me. The first move seems to have a cell that is shared by both ALSs, which I don't quite understand how that works/when it's allowed to use an overlapping cell in ALS-XZ like that. The second seems to have two RCCs which I only have a light grasp on, but is also eliminating the 6 in R4C5 and I don't understand why. And both have a chain/ring drawn over top that I don't know what it is communicating. If it's just showing that a ring exists, why is it included in both these moves specifically? And why would it not also eliminate the 5s in R8C67? Any help explaining how/why any of these work would be great!
Here's the puzzle string if you please - 040502000180004005000008790804000000050000010000000802071900000200400078000206040
And a Sudoku.coach link for anybody who wants it - https://sudoku.coach/en/play/040502000180004005000008790804000000050000010000000802071900000200400078000206040
(As a completely separate issue, does anybody know why this solver sometimes shows nice loops and other times AICs? Wouldn't it make more sense to only show AICs?)