I would not do what some people do and overclock the Switch close to stock X1 speeds.
A moderate overclock over stock handheld mode speeds is fine. But the battery seems to really not be designed for the power draw of docked mode.
To those that think it's fine if you don't do it often, that's not how batteries work. If you draw enough power to cause the battery to heat up above its safe operating temperature it will damage the battery (if even just slightly) and that can happen in minutes. A moderate overclock somewhere in the middle between stock X1 and stock handheld Switch should be the highest you ever go, and even then it's a good idea to make sure the left side of the Switch (where the battery is) doesn't heat up much.
Anyway, on the SoC side of things, I doubt you would be able to do any damage to it by overclocking. It doesn't get especially warm in docked mode - it barely gets lukewarm, and I have heard from tests done that even covering up the air vents with cloth isn't enough to make the system overheat and shut down, you have to actually unplug the fan to make it overheat. And my phone gets noticeably hotter while gaming than my Switch does in docked mode, but that's also made of glass and metal with no plastic in sight, so I'm not too worried about it.
To me it seems like Nintendo did a decent job with the cooling solution. They probably had some issues with it throttling or crashing at stock X1 CPU and GPU clocks which is why they clocked down the CPU. But any modern mobile device will throttle aggressively to keep temperatures in check. Considering that, I think Nintendo did a pretty good job in getting a decently performing mobile device that doesn't throttle, and I don't mind that they compromised on the CPU clock as I really wouldn't want the Switch to be any more bulky than it already is. Games look good and generally run well especially in handheld mode on that nice 720p IPS screen.
The issue seems to stem more from cheap plastics used in the case, resulting in the bending and cracking issues that are infamous. The internals might be fine with the docked mode temperatures, but it seems like the plastics are not.
As well as that there's the battery concerns when you're pushing the battery beyond what it was ever intended (by Nintendo) to do. I don't know what the safe discharge rating of that battery is as it varies a lot. But clearly it was never designed for the kind of power draw that some people are forcing it to provide by OCing as there have been a couple of reports of bulging batteries already. The good news is that the battery should be easily replaceable for one that has a higher safe discharge rating. The bad news is that it might have a higher self discharge, or lower capacity as a result if you want it to fit in the same area without making the console more bulky.
Because I hate bad framerate and overclocking helps with that.
The thing is there is no good reason why N64, PSX or anything older than that should have trouble running at stock speeds. Just give it some time to improve and they should run with ease.
Yes but the Tegra X1 already existed, it wasn't made for the switch, I'm saying that compared to nvidia cooling solution theirs is worse and they know it, hence the underclock. It could very well only be about the battery, but I dunno, seems to run pretty hot but the "hand in vent" test.
That is true but the Shield TV is also not a handheld device and it can afford to be more bulky in order to accommodate better cooling. Seems to me like the Tegra X1 was never really designed for mobile devices. Hell Nvidia themselves only put the Tegra K1 in mobile devices, they never went past that.
Just replacing the thermal paste is reported to make a huge difference in how hot the system is
Have you seen the stock thermal paste? The pink color to me just suggests that they used the cheapest paste possible. I've never seen any decent thermal paste be pink, they're all silver/gray.
For those that really want to overclock their Switch long term for increased performance I'd definitely recommend replacing the thermal paste. But it won't help the battery issue; at least the batteries can be replaced, although they are glued in so it's kind of a pain.