I would rather see people make bets that they think are very profitable (relative to the size of the bet).
There’s this idea that betting on your beliefs is epistemically virtuous, which sometimes leads people to be so eager to bet that they make bets at odds that are roughly neutral EV for them. But I think the social epistemic advantages of betting mostly depend on both parties trying to make bets where they think they have a significant EV edge, so sacrificing your EV to get some sort of bet made is also sacrificing the epistemic spillover benefits of the bet.
The appendix of the ebook (pdf, p. 218 & 221) suggests structuring it like tax brackets, giving (as a percentage of adjusted gross income):