I am making things work, but am on about Mark III with the solos. The problem with the solos is first, not overwatering them from the same pump the big pots are on, and second, distributing the nute mix early on when it does not pool on the top of the medium because the medium is plugged with roots.
I dealt with the distribution hassle by putting a synthetic cloth sleeve over the DIY halo. The cloth prevents the water from shooting out in one spot under each hole, and may help get it around the pot a bit. It looks like this will be my go to unless one of the smallest square Floraflex caps will work on a solo, which it might if my initial size estimation is good. The other thing I have now confirmed with my solo mischief is that I have to leave enough head room above the medium to contain a full dose of nutes. The problem is that with some solo plants, the roots eventually get so dense in the pot that water takes a long time to penetrate to the point of runoff - much longer than a normal fertigation cycle for less tight pots. So, if mixing pots sizes, sometimes solos will flood over the top unless headroom will contain an entire dose of nutes. This issue has so far happened with two of the half dozen or so solos I have grown, and it ain't easily fixed any way other than more headroom. An alternative is a separate pump and timer for the solos, but I am trying not to do that.
The bigger rings on the big pots are working fine as far as I can tell, all the big pots on auto watering are thriving, so it seems that the cloth sleeve that I put on the solo rings may not be helpful in the larger pots, at least not for distribution of water around the pot. The sleeves also keep medium from splashing onto the rings and being siphoned into the holes though...
All considered though, if I stick with the current pot setup for the next grow, I will see if one of the round floraflex caps will work on my large pots. They solve the medium getting into the halo holes, they distribute the water well around the pot, they keep the top of the medium moist, and I would not need emitters to supply them because I have tube clamps on the supply lines to adjust the amount of nute mix to send to each pot. All I would need is the clips that hold a 1/4" tube to the tray on each side. At this point, I don't even use clamps on the supply lines to the large pots. Feed to the large pots is adjusted exclusively with the timer on the pump. Once the feed to the big pots is sorted, I use tube clamps to reduce the feed to solos to the appropriate runoff. The basic setup is working just fine with one pump, as long as feed to the solos can be reduced with valves, or in my case, tube clamps.
Happy fertigation peeps.
very happy and just order more 
I feed the caps with(2) .5gph pressure compensating drip emitters… during flower when plants are drinking the most I bump them up to 1 gph I didn’t think I was getting enough feed with the .5’s once they got older.
