Funky varigation/mottling on mature growth

Hi all, just wondering what might be causing the varigation on these mature leaves. This is a Kali Mist from seed, and the only one of 8 plants displaying this condition. I kind of have a suspicion it might be related to manganese, as my tap water is rather high in it, but would like some others' insights.

The plant is otherwise rather healthy, and this pattern has developed over time in the mature leaves. I'm not terribly concerned as it's almost time to take her down, but I'd like to figure out if this is something to keep in mind for the future.

The plant is in an organic soil mix similar to Cootz recipe, supplemented with a 5-7-3-2 Dr. Earth nutrient mix @3cups/cf, and botanical teas. TM-7 every other watering; Ful-Power, Protekt and Aloe every watering. Very few foliar feeds restricted to PM intervention.

I feel I may have seen a post at some point regarding something like this in outdoor potted culture. This plant has been growing on my deck all summer.

Thanks much!

I had some leaves that looked exactly like this, i thought i was tobacco mosaic virus, but the plants made it to harvest with no issues.

the plants were in cold temperatures 50's at night and 60-75 in the day. not sure if that had anything to do with it.

SofG

I considered TMV as well, but the plant isn't expressing such intense contortions as I've seen others with TMV do. This problem has also been developing for weeks, and if it were TMV at this point I would expect it to have also affected some of my other plants (especially as I haven't been doing any pest control to prevent insects spreading it), but not so. My temperatures have been something like that for weeks at this point, so that may be something.

Thanks much!