Farming Gatekeepers for the MO: our only hope?

It's pretty clear by the current progress that this MO is not one set in our favor; the enemies required for each kill counter are difficult to encounter in any large numbers, with the Gatekeeper being particularly rare. Unlike our fellow divers, though, I have been able to clear more than a handful each mission, and offer the following for those looking to take these future trophies out:

Where are they: KARLIA and SENGE 23, DIFFICULTY 10, Evacuate High-Value Asset Missions

I know that can be a big ask for plenty of you, but this is how we're gonna see the most action. Gatekeepers spawn most often as squid reinforcements, and these missions are where we're the most prepared for them to come. There's an average of 3-4 per wave at this D10, but with the right team loadouts, they never get the chance to touch a diver.

If enough of us spam these missions, even the suspiciously low spawn rate for this MO can be countered. Pack your sentries and get diving.