When you dump you want to really dump.  The rush of stuff out of a mostly full tank has the momentum to carry more with it than if you dumped a total of, say, 4 gallons.  So, yes, the fuller the better.

Of course you can dump anytime though.  If you do dump only a few gallons there a few things you can do to mitigate the potential problems.  Before you dump, run as much plain water down the toilet as you have the patience for.  Or, after you dump, fill the tank with water and dump it again.  If you have the black tank washout thingy, hook that up and run it for a while after you dump.  These are all options.  Some people can get real fastidious about rinsing their tank.  One idea is to keep the sensors clean -- the ones that work the lights that tell you how full your tank is.  Those never work anyway, so don't worry about trying to make them work.

Other tips: use a dose of chemical in the tank right after every dump.  Always use more water when flushing than you think necessary.  Dilution is the solution.  Don't overdue it, especially when dry camping.

Welcome to the forum, and congratulations on your new Pod.  This is the place to come for RPod questions.

TT

Now I come from the darker side of life and don't poop in our toilet. No poop, no paper, no jam-ups. 'We' utilize our toilet like a composting toilet and Wag-Bag poop when required. We started this system years back and continue to this day. It's funny how simple it can be vs. spending $1k for a composting toilet that has it's own issues/system/usage. 

For cleaning the tank, I  haven't fully decided upon a agent I'm fully happy about, yet an agent added in and a 1/4 tank does get a lot of sloshing going on to clean and semi-scrub the tank. I say this as when we travel. When I get home I use bleach. I like what folks are doing with ice cubes and it makes sense. Yet... on the road, ice is a valuable commodity. 

Like I say, I come from the darker side of this. LOL

Avoiding numbah two in the black tank as much as possible is a good strategy 

Use a good biological tank treatment such as TankTech's Rx or Unique Products' RV Digest-It or Happy Camper, etc. The live bacteria and enzymes of this type product will help break down solids, something that chemical treatments that only mask the smell can't do. The second thing is always to use adequate water when doing #2. Fill the bowl at least half-way and lay toilet paper in a cris-cross pattern on top of the water. Do #2 and then add even more water before flushing. By doing this, there will be sufficient water to avoid the "pyramid of poo." Brand of toilet paper is less important than using adequate water so that the solids can break down and move out when it is time to drain the tank.

I agree that the black water tank flush fitting is inconvenient, but the way it is installed, it is better than some setups I have seen where the city water connection and the black tank flush are in close proximity.