You guys really need to slow down and actually think this through, it's not that tough.
One of Scum and SK do not know if Profii is the tracker, so their NKs need to account for that. If he's the tracker they both want to kill him, if he's lying then the other faction still don't know and want to kill him. If we lynch Shad we basically give info to killers to use overnight, ie they can react to the information before we can.
Scum!Profii = SK thinks he's tracker and wants to kill him. Scum search for the real tracker and kill them, so even if the SK doesn't kill Profii the tracker flip confirms Scum!Profii and non-Scum!Shad (Shad could still be SK). (Probably dead Profii and dead Tracker)
SK!Profii = Well scum know he's either SK or tracker, either are a super high value target, Profii gets shot. Profii has to shoot scum at this point to have any chance of winning, since his only hope is a doc protect keeps him alive for 2 nights and he somehow doesn't get counter-claimed. This situation is extremely unlikely, pretty sure Profii isn't SK, his path to win is gone basically. (Dead Profii maybe dead scum)
Tracker!Profii = One of scum or SK know he's the tracker, so they're going to kill him or scum. If Shad is scum then they'll submit with Shad while they can and may or may not kill the tracker, but they know we're not killing the guilty tomorrow if it gets to it, their best shot is to go for an SK. If Shad is SK, then he's just fucked, he can do whatever he wants. (Dead Profii and random kill)
In all of these, we know the veracity of the guilty claim tomorrow, and it'd get counter-claimed tomorrow anyway.
Ok so what happens if we flip Shad today:
Shad!Town: Profii is scum and SK knows they're tomorrow's lynch, SK kills elsewhere looking for real tracker or scum or the doc. Scum go for the real tracker with Profii submitting the kill (tracker can't find scum), or SK or doc. (Town lynched, two NK shots at town PRs most likely)
Shad!SK: Profii is most likely tracker and gets NKd by scum unless lucky doc. (SK lynched and Tracker dies overnight)
Shad!Scum: Profii is tracker and gets NK'd by probably both scum and SK, basically dead tracker. (Scum lynched and Tracker dies overnight)
By lynching Shad we're giving information to killers to use in the next phase. If we hold off on the lynch of Shad, we lose no information, and we are the ones coming into tomorrow armed with information.