So, After doing some testing from 2018, 2020, 2021, 2022, 2023 (for some reason I can't find any 2019 install files). It looks like I may be downgrading all of our production work to 2018. All the bugs that we experience in 2020 and on weren't present in 2018. I think I will have to do a workaround for the newer double wall duct functionality, but that's the only thing I can find which is way outweighed by a lot of other (mostly) designline issues.
I'm going to have to upgrade the database for 2023 for management due to the design side, but it shouldn't really affect the ESTmep side.