So here is what I did in terms of re-configuring/improving/fixing the ducted vents...
1. Plugged the two vents just in front of the garage AC and the one vent next to the bedroom AC. I don't see the point of these. Can get the airflow you need with the vents on the A/C. With these vents open going to have a much harder time getting flow to the other ducts at most will come out of these vents a basically the path of least resistance.
A. To plug the bedroom vent, made about 1in thick foam out of several
layers of some thin rolled foamed that others have used (as proper
closed cell type to handle moisture properly) to put in the
~5in vent hole and taped it. Want to be careful however you do this as
don't want it sticking up into ducting much as it would then restrict
flow to the other vents on the same duct.
B. *** This one only applies to me since I had a damaged duct per #3
below or for those with other configurations/reasons want to plug
directly at the AC unit **** Since my the one vent in bedroom was
now the only one connected to the right side duct outlet on the AC
unit, I used some pipe insulation that was about 2in outside diameter
and carefully squeezed it into the duct then taped it off. to ensure
sealed.
This is the pipe insulation used for this and #2 and #3 below to terminate going into extra ducting. I taped around it afterwards to ensure fully sealed.
2. Blocked the extra ducting that extended off the front bathroom duct and the living room one.
A. Used the pipe insulation for this also and basically took like a 12in
piece and did the best I could to wedge it in as a v-shape just behind
the vent hole. Taped around and over it to as well and tried to go over
the hole inside the foam at the ends as best as possible.
3. Terminated the duct that both AC's would have been connect to. I don't think this is a good idea as they might fight each other and when one is not on that is way too much volume for one A/C to try and feed into IMHO.
A. I actually had no choice as my duct near the kitchen/front door was
destroyed. I plugged this vent but would have been nice to keep it. I
would have used the pipe insulation to terminate the duct just behind
this vent to separate the two AC units. With the bedroom vent plugged
this would be only one on right side of bedroom AC so would get really
good flow then to help with living room cooling.
B. Terminated the duct at the left side of the TV/closest to patio door with
the pipe insulation so it would be the only one on the left side outlet of
the garage AC and it gets really good flow now.
4. Unscrewed all vents from the ceiling to inspect properly and repaired all that were not taped properly to seal the roof heat from the vent hole. As mentioned I had some that were essentially completely open and only a couple had just minor gaps. Did this on all, even the ones I plugged just to ensure sealed as best as possible from roof heat.
Not great, small leaks
Really bad!
Fixed
5. Put the divider in the AC back up and position properly and taped it so will hold as mine keep falling down. Just need to remove outer plastic cover to do this as fair amount of working space. This is critical or wont get much cold air from the AC units to start with. Also taped it up as don't like the non dense insulation seals they use and mine were starting to tear or had some gaps between the housing. Taped up all the ducting, etc. inside the A/Cs as was just done poorly to start with.
Divider fell over
Divider stood back up but no tape
Taped divider
**** Had to split this original post ... see few posts down to continue ****