Soldato
But its investing in another motherboard thats pretty much EOL now unless you get a cheap used one to do you over for now. I can see the attraction though if the uplift is above and beyond what the 9900k can do now.
I'd lose the term investing really, you can dump a brand new 5800X3D in a £50-60 AM4 B450 board and get the same features you have in the 9900K based Z390 give or take a few I/O options, and you'd end up making money on the Z370/390 board when you sell it, in fact you could probably swap to a 5800X3D + B450 after selling a 9900K/Z390 combo for less than £150, maybe less than £100. 9900K is still fetching nearly £300, some assume £230 for a quick(ish) sale and £100 for your board, again quick sale (assuming not a terrible board), you've got £330, so £409 for 5800X3D and £60 for a board, total £469 - £330 = £139.