It really depends on your usage type and your reason for wanting to turn it off in the first place.
TPC is there to auto dim the screen when it detects there have been limited changes to the APL (Average Picture Level), i.e where there's been static content for a while. On the LG OLED TV's this is quite aggressive. For PC desktop use this can happen quite a lot, I'm currently using the 42C2 and after a couple of minutes it will dim the screen a fair bit. You need to remember though that it doesn't change the fact the image is still static with limited changes to the APL. All it's doing really is reducing the brightness of the OLED pixels in an effort to try and reduce the chance of burn in. The brighter the pixels are operating, the more likely burn in could occur. So the logic being is it will reduce the brightness a bit to try and help.
Really this TPC feature is there with TV usage in mind, after all this is a TV primarily. So it's there for occasions like if you were leaving the TV paused, or away from the screen or something. In that kind of usage, it might as well do that for you to try and help a bit, it's no real concern. The only issue with that for TV usage is that sometimes a scene that is
meant to be fairly static, especially common on darker scenes, could trigger this TPC unnecessarily even though it's still a changing and dynamic scene. For tactual dynamic content with any moving image like a TV show, movie, game etc it is really unnecessary to do that and it's not really meant to do it either. It's kicking in when it probably really shouldn't. So for TV usage, that's when some people want to turn it off via the service menu to avoid that distraction.
That's a very good reason to do so, and the only "risk" in that is if you are in the habit of leaving the screen paused or static, it will no longer activate TPC and try and help you a bit. For the actual dynamic content it will have absolutely no risk, as it's just stopping something from activating that shouldn't be activating anyway. If you do disable it you might want to be a little extra careful to not leave it paused or on static screens, but as i said earlier it's still a static image either way - it's just a slightly darker static image with TPC enabled and therefore a bit more risky.
Although having said that you do have to go some to actually cause any real burn in issues on an OLED TV
For PC usage it's a little different and probably more annoying and likely to be experienced. TPC will activate when there's limited APL changes, dropping you from your normal brightness down to a lower level, again to try and help reduce the risk of burn in. But you could achieve the same thing in effect if you just operated the screen at a lower OLED light level (brightness) to start with. TPC will still kick in and dim you even further, but it's not really needed then.
For example (made up approx numbers) if you ran the screen at 100% OLED light level that was operating at 250 nits, when the screen detects static content and an unchanging APL, it might dim you to the equivalent of say 75% OLED light and 180 nits. You could have course instead just run the screen at 75% OLED light level all the time and disable TPC and that would be the equivalent of you always operating in the "safer" mode, if you see what i mean?
If you want to consider turning TPC off, the trick would be to find an OLED light level that is comfortable and appropriate for your static desktop use, and that has a lower chance of burn in. I expect for most people a setting around 50% OLED light giving you a 120 nits approx luminance would be appropriate and comfortable, but you would probably find that's considered a low OLED light level and therefore a safer, less likely to cause burn in, brightness level. Remember that TPC is a safety measure, it has no real link to the actual brightness setting, it just dims the screen when it thinks the content is static for things. If you're operating the screen at a lower OLED light level like that, it's of minimal risk to disable TPC. With TPC enabled i expect what most people end up doing for PC use is setting the screen brighter than they would normally want it, putting up with that for a few minutes, then letting TPC lower you to your comfortable level. That is of course pointless and "worse" from an image retention point of view than just leaving it at the lower level all the time
I don't see there being any real risk in turning TPC off for PC use as long as you're not going to be running at a really bright OLED light level all the time and then leaving the screen really static. There is far more benefit from a burn-in mitigation point of view in being careful with your content, moving things around, hiding task bars, setting screensavers etc than there is in letting a feature like TPC dim you a bit sometimes when it feels like it! And if you're using the screen primarily for its intended usage like gaming, movies, HDR and only a bit for office /static work, it's a really small concern anyway. If you're mainly using it for static/office work, you've probably brought the wrong screen/panel tech to start with!
