Wasn’t the underlying idea to get people to team up to take on these features? In light of that I don’t think a new solo method is likely to be implemented by ccp.
The NPC fleets make mining a bit more challenging which should create an element of scarcity and support prices. I think the main problem is balance - the NPC fleets should also be active in Nullsec belts & anoms!
Better solution.
Just turn belts into sites that respawn on a timer (belts nearly finished should despawn on a timer also to prevent leaving a single rock wrecking the spawn system) Fewer per system to reflect the timer respawn.
Now it doesn’t matter if they mined them out 12 hours ago, there will be a site available most likely in system and certainly one a jump away if it’s just npcs doing it.
And there is benefit to chasing them off as they dont take half the belt. Plus competition as resources available at a given time are less, even if as much or more through the whole day.
The best way that I have seen to deal with this is to kill them. You need two characters. One in a ship with dps and combat probes (t3d’s work well because of the bonus to prob launchers) and another can be anything, including a rookie ship.
Take the rookie ship and fly to the belt with the miners. When you are near create a bookmark (ctrl-b.) It needs to be about 1k-8k away so if it is not then try again. When you have that bm, warp to the belt and shoot at one of the npc’s. After about 7-10 seconds warp to the bookmark and start aligning away from the belt. The response fleet will show up in the belt, target and shoot at you. They should miss. The miners and any hauler they had will fly to a safe spot.
Use the scan/dps ship to find the miners and kill them all. There should be no response fleet at this spot. Miners from that npc corp will not respawn before the next downtime. You also get any ore/loot they drop as a bonus.
To do this with the Guristas and Blood miners you have to use a cloaky ship at the belt so you can set up before they respond. In this case you don’t need to shoot at the belt, they will chase you without it. There is a bug I have seen sometimes where they just sit there and do nothing though. This won’t help you if the roaming gang of 5 or so frigs decide to pay you a visit.