Smallsat missions to main belt asteroids - possible? Options

[antipode]

Many of the large main belt asteroids (2 Pallas, 10 Hygeia, 704 Interamnia, 52 Europa, 611 Davida to name just a few of the biggest ones) remain unexplored by spacecraft.
Some of these are suspected as being protoplanets. Their orbits are highly varied. Their surfaces vary. Some have moons. They are interesting targets in their own right.
But how to do it, and affordably? Its wonderful that we have upcoming missions to 16 Psyche and the Jupitoer Trojans but even these Discovery class missions are expensive and highly contested.

My question to this knowledgeable audience is threefold.

1) Does anyone know of any existing mission proposals to other main belt asteroids?
2) Do advances in smallsat launchers (ie Electron) and rideshares allow low cost opportunities for cubesats (6U/12U) in this missions space?
3) Would orbiters be possible within these mass limits, and if so what sort of instrument suites would be desirable and possible?

Phil

ps moderators, if this is in the wrong space feel free to move