Thank you for the suggestion but in my opinion any limitations in visibility of proposals and restrictions on who can vote to limited group(s) are opposite of decentralisation.
For this reasons I’m suggesting to cancel the proposal Rejection Cost and relace it with Spam Rejection Cost, where the cost would be significantly increased and Spam would be identified by more than 50% of votes (check box Is Spam with every proposal, equivalent option for cli…).
(rejection cost was meant to be spam rejection cost anyways)
In my opinion this would even encourage serious proposers as there would be no cost of good-faith (discussed here etc) rejected proposals.
Spam would be gone due to high Spam Rejection Cost, and would be decided by whole community via simple click during voting (or adding --is-spam on cli)