please review or advise on my upgrade strategy (RAM + CPU on asus prime x370 pro)

[Snarf]

Budget (including currency): 400 - 600 euro (plan: upgrade early next year, end of this year if inflation keeps picking up and/or euro dollar exchange rates keeps worsening)

Country: Netherlands

Games, programs or workloads that it will be used for: Mainly productivity needs in the form of quantum chemistry codes and coding on the days I work from home (can't be bothered using the citrix vpn environment my employer provides), and mostly world-sim games like the Dishonered, Hitman, and Deus Ex series and the occasional Doom eternal rampage or Civ 6 on the weekends (mostly CPU intensive games). Usually my games are rendered in 1440p and played on my 65" 4K oled living room TV capped at 60Hz. Since I mostly play slower / stealth games I prefer to run games with all the eye candy on and render at a resolution that gives me a stable frame rate between 50 to 60 Hz

Other details
current rig:

asus prime x370 pro
AMD 1700X (core multiplier locked at 38.00)
4*8GB Ripjaws 2800 MHz
RTX 2080
good 800W PSU

What I mainly would like some advice on is whether it is worthwhile and cost effective changing the upgrade strategy I've been using for the past decade and a half. 

The past decade and a half I've been building a completely new rig every three to six years (excluding GPU). My old rig I usually sell cheaply to a friend who just wants a PC that is somewhat better then a console and also does steam, word and excell (to recoup the cost for a PSU, cooler and case). My aim has always been to build a fairly balanced and somewhat cost effective rig. (I freely admit that buying the 2080 half a year after launch was a huge mistake, though it was quite the upgrade from a 2x RX480 8GB crossfire setup.)

Given the price increases for the new platforms, the ridiculous DDR5 prices, the fact that I really wouldn't benefit from a faster pcie4/5 NVME storage solution / bootdrive the next two to three years, and the coming economic storm, I'm considering to upgrade my current rig to squeeze a bit more life out of it.

 

I'm purely considering upgrading the CPU for the gaming aspect. A new CPU will be better for my productivity workloads, but it really is not necessary to upgrade for that. In the newer titles I have noticed that CPU frame times can be quite high. In upgrading my CPU I hope to squeeze out a bit more life out of my 2080 untill GPU prices are no longer in cloud cuckoo land.

The plan:
Given the work I do with the machine i'm perfectly happy with an 8 core CPU, and that my work related performance is not really helped  but worse with the 3D cache of the 5800X3D, it really is a no-brainer to upgrade to the 5700X or 5800X. A 12 core CPU would be nice, but the productivity benefits do not really outweigh the costs.

The questions:

1. Does the community agree that squeezing a bit more life out of current system is the best compromise on performance and cost for the next two to three years? The other option is to save a bit more and build a completely new rig somewhere late '23.

2. Currently I have 4*8GB sticks of 2800MHz RAM. Would it be worthwhile upgrading to 2*16GB sticks of 4000Mhz (+/- 100 euro) or 4600MHz RAM (+/-130 euro) if I upgrade to a 5700X / 5800X?
Additionally, the QVL list of my prime X370 pro hasn't been updated since 2018, even though the BIOS has been updated to allow for Ryzen 3 chips, how do I know or figured out if my CPU + MB combo can run RAM at these speeds?
16GB is too little for my needs, more then 32 would be nice but absolutely not necessary for the next two to three years. 

3. From a gaming perspective, would there be a convincing argument to buy a 12 core CPU? Is there some expectation that a 12 core CPU would be better utilized in the coming years?
My educated guess is that it is not, and that 8 cores will serve me well enough.