Question Storage Setup

[chaosbib]

I currently have a 1TB 2.5" HDD (WD Blue) for general mass storage and a 256GB SATA SSD (Crucial BX500) for my OS and few games. I recently built a gaming pc (storage was recycled) and am planning ahead for storage upgrades. I am still deciding which one should I pick and/or if it is reasonable to upgrade at all. I have 64GB free left on SSD, and 760GB on HDD. My motherboard (B450M Steel Legend) have 2 m.2 slots which I wanted to utilize and I can go (look at the poll choices):

I have enough drive enclosures to re-use the drives that will be replaced just in case. I just need some suggestion or guide to clear my mind. Thanks

Edit: I mainly play AC:O and LoL/DOTA, but will be playing some "heavy" games in the near future.

 

[USAFRet]

Add another SSD (of whatever type), and use the old HDD for backups.

Games don't really benefit from an NVMe drive, much less 2 of them.