Re: Doesn't TrueNAS Scale work just as well on the HP Microservers?
I recently upgraded an N54L to 16GB (2x 8GB) ECC RAM - just buy the known/recommended ECC RAM sticks (mine is Kingston, that I picked up for £40 the pair).
I mostly us it for storing movies and documents/git repos in a home environment (SMB & NFS).
It all runs great with TrueNAS Core and about 40TB of storage across 3x pools (2x RAIDZ-1, 1x mirrored & encrypted).
I have the 4x internal HDD plus 4x SSD drives (in a 5.25" cage in the CD slot) all hanging off an LSI-9211-8i, and a 2x drive JBOD connected to the external SATA. Boots off an SSD connected to the optical motherboard SATA (and I still have the 4x SFF-8087 motherboard SATA ports available!)
To be honest, changing the RAM was no big deal - it takes about 5-10 minutes to get the motherboard out and back (closer to 5 once you've done it a few times) and it's not really something you need to do often.
I ran FreeNAS 9 on this for years, and made several customisations (MySQL jails etc.) which bit me in the arse as it massively complicates OS upgrades, so now I keep it simple and stick to the plain TrueNAS system and upgrades are a breeze. The MySQL etc. runs on an RPi4 instead (and is actually better for it).
I'll probably stick with TrueNAS Core 13.x from here on out, but maybe keep an eye on any fork.