If the orca doesn’t stay on the mining grid, then what’s the point of using an orca in the first place?
Assuming barges/ventures are on the mining grid, and the orca just picks up the ore and then warps off, a DST would do that job a lot better, as it aligns and warps faster then an orca. As in getting ganked, it won’t change a thing to get rid of the foreman burst undock prohibition, because a ganker would park a bomber alt at a ping on the station the orca offloats, another bomber alt at the mining grid close to the miners, and wait for his eye on the station grid to see the orca entering warp. Right after the orca enters warp and will not be interactable until it lands on the mining grid, the gankers then spikes local with their dessie swarm and warp all dessies on the bomber that is on the mining grid. Because the orca warps slowly and warp accells/decells slowly, the dessies might be able to land on the mining grid before the orca does, and the orca will land right on top of the dessies. That’s a dead orca. A real hauling ship can bounce at a ping on both the station and the mining grid and still make it to the miners before they deplete their mining holds, but an orca lacks align time, warp velocity and warp acceleration.
And that’s why noone uses an orca that way.
But if you want to use an orca to haul, instead of a real hauling ship, why not use a command dessie to boost the miners instead of the orca? The orca could then do it’s haul thing w/o weapon timers while the command dessie stays on grid. A Command Dessie is an order of magnitude harder to grab then an orca, and can, if not scrammed, boosh either the miners out of a dictor/hic bubble, or can boosh the gankers out of engagement range to the miners, making it a top-priority gank target as not prioritizing it will allow the dessie to save the miners. With a mining foreman implant, a command dessie provides a better foreman buff then an orca w/o the implant, and you can buy 10 fitted command dessies and faction implants for the price of one unfit orca. The only thing it doesn’t give you is the ability to crab compress on grid and the last 10% extra mining burst effect in case you combine the skill-maxed orca with the implant. A self-buffing mining Battlecruiser might be a thing, too. A BC is easier to gank then a dessie, though, and can’t boosh off the other mining ships.