In my fucked up brain I still just can't buy that the election was legitimate.

[Farmer-Rick]

91. Many countries do routine audits of election results

And investigate concerns of rigged elections. It's very common especially with computerized voting.

That's how most fraudulent elections are discovered. There is plenty of probable cause for investigation into the 2025 presidential election. Probable cause is a type of evidence and is very credible. It is used regularly in police work.
Probable cause is the basis for most police investigations. To get more direct evidence an investigation has to be done. If an investigation were ever to be completed, there would be plenty of evidence for prosecution.

Here is probable cause, which is a form of evidence, for investigation into the rigged 2025 presidential election:

Russian initiated bomb threats at polls, uptick in rejected ballots, group of prominent computer scientists and election security experts raised alarm over breaches of voting system software, and everything the original poster has explained.

There is evidence and creditable evidence to initiate an investigation.