Absolutely nailed this bacterium lark now.
Found first plain, nothing doing, but I've sussed now that in any given dust bowl they are either there or they ain't, so don't spend 20 minutes hoping.
Took off, flew northeast a bit (I'd landed near sunset stupidly), found a second plain which was more of a plateau and was the paler green-blue on DSS, landed right on the edge of it so there was no chance of me accidentally driving away from the biome (because the "wrong" directions were all cliffs so I simply had to remember not to drive off any cliffs, who needs a compass?), and in the time autoland was jockeying around, I spotted one using headlook. In, out, done, and then I set off northeast having noted the plain was longest in that direction.
Waiting for 500m ping from BioInsights, raised turret, slowed down, there it is, done.
Took a risk and drove off at right angles for the next 500m leg, and that ended up being a km away anyway so I might as well have kept going the direction I was.
Got tectonicas as well and that was super easy, I landed in a basin and it was full of them, so I just went to extreme edges of the basin to get the distance.