Finally got some extra money to upgrade the lab, I was starting to worry about running out of space...
I picked up an HPE ec200a after reading about it on ServeTheHome, an online forum for homelab enthusiasts. It's got a modern Xeon D-1518 (4c/8t), Can hold up to 64GB DDR4 ECC, 2 drive bays, 2 NICs, iLO and an M.2 Slot!
So-far, it's been a super great addition to my lab, I offloaded storage to my NAS via NFS, and boot Proxmox as a hypervisor off of an M.2 SSD. I ended up loading it with 16GB of DDR4 ECC to start, but I plan on adding another stick eventually.
I also acquired a better UPS, an APC Smart 750w UPS. It's got a 2-battery setup, a nice informational display, and of course NUT support for connecting to my Synology NAS. Had to rebuild the batteries, they were from 2011! Well overdue!
I've also started working on rebuilding my on-premises AD setup, first starting with learning AzureAD Sync so that I can SSO between AzureAD and on-premises AD. So-far so good! I can sign into my NAS with the same credentials I use for O365!
Finally, I've also started implementing concepts I'm picking up at work, DUO being one I really liked. DUO permits MFA on the hardware level, securing access to terminals, desktops, laptops as well as online services. I've implemented it on my personal laptop, and my on-premises DC! I've also implemented it into services like Bitwarden!