Also in Meat when Dave and Karkat have the conversation about how only one of them is really immortal...it got me thinking about this whole "Sburb has Passive EXP gain and they're all still gaining levels" theory. I think Karkat won't Godtier but that he will probably still experience reaching a skill point cap like in a video game. When you have so many skill points that you could potentially spend but you can't because it's impossible for you to actually advance in that direction, its not improbable that the game would stop you from accessing other parts of it before you used those points up. And Death is a game mechanic in Sburb quite literally. SO, with THAT in mind...They might be unable to actually die for real if the game is glitched in this manner and won't let them advance. (Also a large part of the Epilogues and Beyond Canon's themes is stagnation.)
My theory within a theory is that Karkat and possibly Kanaya are both immortal because of this passive EXP gain and they will only stop being immortal until the game fixes itself and the glitch finally stops (which can happen in games) OR...you know, they just godtier in the new session and finally break that skill point ceiling. But even that has disastrous consequences lol. For instance, have you ever killed a bunch of mobs all at once in Minecraft? You get a shit ton of EXP that way sure, but did you know you can gain more levels than the game can count and it'll fuck the game up and make it crash?
If Sburb can't crash because they have to win, I fear Godtiering either of them would be really bad in this scenario because then the game would have to find some other way to get rid of the anomaly fucking everything up. What I'm saying is, they could Godtier and then immediately blow up or some shit from how much EXP rushes to them. Like the worlds worst power up T_T