Firstly I don't have this CPU I use a 5900X but I do have some thoughts around some of the choices made here, however missing a lot of context around your system and how it is used so I am just going to assume you're primarily gaming with it as it's a safe enough bet around here and frankly if you were running full on heavy number crunching tasks on your CPU it wouldn't be maxing out at 60c it would be much, much more.
So, the only reason your max temp at 4K is 60C is because the cpu probably isn't really being hit hard at all, the GPU will be instead I would say, so very likely 100% GPU usage to perhaps 20-30% CPU usage. If you were to actually hit the CPU hard with the power limits off, it would most likely be 90c + very quickly with that cooler, probably 100c + actually. You really can only aircool these with a Noctua D15/s or a BeQuiet Dark Rock Pro 4 or something similarly girthy with lots of mass and surface area, most people seem to use a 280mm or 360mm AIO's, which leads me to the motherboard. That particular motherboard is so built up around the CPU socket I really get the impression Asus intended it to be used with watercoolers not big hsf units anyway, probably because the intended use profile for a board like that would involve a chip like you have and therefore water cooling.
You may not like what I am about to say but my own thoughts looking at this are as follows; so apologies if I am telling you how to suck eggs here, again I lack a lot of context around this;
But, the thing is to run a 12900KS the way it was 'meant' to be, you need to build the rest of the system around it (and the GPU), keeping it cool and such, if you compromise cooling to fit your case or motherboard rather than buy those to fit the demands of the CPU then your rather wasting the money you spent on a 12900KS I think, you might aswell buy the K or really just a 12700K as the K isn't really easier to deal with than the KS anyway it just costs a lot less. I gather this is a transitionary upgrade and you're going to put a better GPU and more modern faster monitor in later as it's a very imbalanced system right now, the 4K monitor is nice but again if gaming there is just no point in any of this without using a high refresh rate monitor, I would say a 4K one for this system aswell. I use a high refresh 4K monitor (Samsung Odyssey G7 S28) with a 3070 and it's very nice although I would personally like more GPU and mine is about 30% faster than yours and assuming you put something equal to your 12900KS in at some point, perhaps a 4080/4090 when they show up ...you're gonna want a lot more than your 60hz 4K monitor can give in my opinion, or I would at least, because you don't buy a CPU like that to play at around 60fps. If you turn v-sync off and let it run too high you will get tearing and you've got to deal with the higher input latency of a 60hz native monitor awell as that introduced by v-sync itself which you will need, to keep a lid on the frame rate with a better GPU a lot of the time as I don't believe that monitor has any kind of adaptive-sync, again, all of which doesn't become a 12900KS. It's the sort of chip you use when your whole system is maxed out really. As I said I am assuming gaming use here from what you did say and right now you've gone very heavy on the CPU but don't have the GPU or the monitor to really benefit from it (in a gaming context).
