I see what you're saying and there is definitely some discussion in some of the media, particularly those media outlets that specialize in pandering/catering to conservative audiences. But I didn't seen any "evidence" discussed in either of those links.
You did say "evidence" of fraud. In fact, you said "substantial evidence," which leads one to believe that there is at least enough that one can review it.
The first link mentions Fraud twice: once in the title (which turns out to be misleading) and once near the end when the article claims that "Minnesota was facing vote fraud problems even before the election." But the author doesn't specify where the alleged fraud is, making his title more like Chicken Little's fearmongering among the bought-in conservatives.
The second link states, "[t]here are questions of possible voter fraud by both parties at the polls," but there is, again, no evidence presented for fraud in either case -only that there are "questions."
I'm still interested in the allegation and if there is, indeed, fraud, then jail time is due for whichever side and for whomever is involved. But you'll have to forgive me, I'm a scientist and have a slightly different definition of evidence, particularly when it's prefaced by "substantial."