What colour is the System LED flashing?

Depending on which OS you choose, you could just run an OS straight off a USB stick plugged into the back or plugged into one of the internal headers

Use the same IP range at both places and give the 2 NASes the same IP address at both places.

It whooshed over my head lol.

This is a i7-8700 on an Asus Prime H310M-E motherboard.

All I could afford at the time unfortunately.

around 350W at the moment, but I'm in the middle of a data migration.

i7-8700 whitebox VM host

2x HP N54L with 4x 8TB SAS drives, one of them also has 2x 500GB SSD and 2x 500GB HDD

TPlink 24 port switch

a couple of UPSes

Huawei LTE router

probably some other stuff that I've forgotten

Will likely be adding a Dell Optiplex mini PC soon

I do it with an answerfile with a clonezilla image. Simple and works.

I use my work PC.

I was on Heimdall but switched to Homarr as it looks a bit nicer.

I did like Heimdalls integrations with Proxmox though.

Homepage is on my list of things to try out but I just don't have the time to figure out the YAML configs at the moment.

Sounds like a question for /r/selfhosted

I still have a 2RU Intel Rackmount hub with a fibre module.

Does it have any use? nope. Does it look cool? Absolutely.

Out of curiosity, why is VPN not an option?

I would be putting the FTP server onto its own subnet and VLAN and making sure it cant talk to the rest of your home network