Before I take the plunge to HexOS

[renesdk]

Before I take the plunge to HexOS on my current NAS server:

• Intel 4770K
• 24 GB DDR3 RAM
• LSI M5015 HBA (up to 8 disks)
• Boot drive: Samsung 850 EVO - 250 GB SSD
• 8x Seagate IronWolf 2 TB
• Windows Server 2022

When I move over the disk controller will change to a 

• Lenovo 430-16i LSI 9400-16i SATA / SAS3416 HBA Controller 12G in IT Mode

Right now the machine is used as my video and music media server via Emby, and that won't change when i move to HexOS.
Services I will add will probably be:

• Immich
• NextCloud

Is there anything I should be aware of when it comes to the boot drive?
I read somewhere a cache drive is recommended and the boot drive should be at least 500 GB. Is that requirement or just a "nice to have"?

When HexOS has been installed on the machine can you somehow de-autorize it from the machine so the license can be used on a new machine if needed in the future?