According to OEP-55, maintainers should be the ones who:
promptly triage incoming requests that propose changes to or extensions of the component, assessing their appropriateness and/or routing them to proper reviewers
So I think #1 is a good idea, but instead of #2 and #3, I would suggest it could be helpful to have a bot that posts a comment like this on each OSPR or bug report:
Thanks for this contribution, @contributor. This package is maintained by: @Amy and @Daryl. They will aim to triage this within three working days by assigning it a priority and a reviewer. (Current potential reviewers include: cc1, cc2, cc2, cc4.)
I don’t think this approach would work for edx-platform, but it would work for other repos.
I’ve seen similar things used successfully on other open source projects, e.g. here’s the bot from DefinitelyTyped:
In their case, I like how the bot is scheduled to “escalate” to more senior reviewers after a while, until someone is able to give it attention. First it routes to the maintainer of the sub-project I contributed to, and then it escalates to an overall project maintainer after a week.