Hardware Upgrades on A Working System

I am planning to upgrade my CPU, memory, and HBA, one at a time on a working, up to date TrueNAS Scale system.
My system is as vanilla as can be - just one dataset. 1 user.
Is there anything to be concerned with?
Why the upgrades?
RAM is for performance (16g now, could be 128g)
CPU needs to have virtualization (Ryzen3->5)
I do not trust the cheapie SATAx4 PCIe board I am using now. New SAS HBA.
Why one at a time? I’m on a fixed income.
Increased wattage. Anything else?
Thank you for the great product and the flawless April update!