Wagering is a crass mechanism for promoting careful thought, but better than nothing.

I think you're on to something when you say that wagering is a crass mechanism for promoting careful thought. The profit-motive is wont to interfere with a dispassionate analysis of evidence. Big wins and timing the market are mistakes nearly everyone makes. But at the same time, eliminating any skin in the game makes the experience of research positions and gambling worthless. No one has fun playing blackjack without betting.

The possibility of concrete gain encourages those with informed opinions to speak up, while the possibility of loss tends to dampen the enthusiasm and confidence of self-styled experts.

I don't entirely agree. I don't see how the possibility of gains encourages anyone to speak up. If anything, it encourages them to disseminate false or misleading information in the hope of eking an advantage, or at least more profit. Especially with regards to PredictIt, there is no way to objectively verify whether or not someone's prediction in the comments section of a market was (1) hot air to "pump" up or down a bracket choice, or (2) a single-entendre position meant to build reputation, because there's no way to know who actually bought which shares. (Screenshots are less than objective.)

I recognize my failure is my impatience. Rationally, there are a lot of undervalued positions in regards to Democrats winning the presidency, carrying a lot of states in the Electoral College, and individual Senate and House races. But when only playing with a little bit of money, I don't want to wait two months.