"I don't think you can get a nice finish coat directly on top of the bonding agent. At least I had a difficult time, although perhaps a pro would know how. For me, everything slid around too much while you were trying to work it smooth." Sounds like you are not leaving enough material on the wall, possibly using too much water in the mix, and did not allow the bonding agent to dry enough. The layer is about 1/16 to 1.8 inch thick. The mix for skim coating should be about like peanut butter in consistency. This allows it to be pushed out easily but has enough body to be workable. Bonding agents need to set up to tacky before applying the plaster. The water in the plaster will help it soften again and grab. Use of drywall knives also makes covering large areas even more of a chore than it needs to be. A plasterer's trowel makes short work of covering large areas and produces a smooth finish. It takes some practice to barealy raise the leading edge to obtain a good finish. The trowels with the tiny (3/4 inch diameter) handle are not as good as ones with a decent (~1.5 inch) grip diameter.

SOS-feeling like this thread might have the answer I need! Skim coating over a really bad knockdown texture. I have done three coats with all purpose lightweight joint compound overall it’s looking pretty good! Only issue is there are still some high point from the knock down still showing through. I don’t think I can sand them at this stage without destroying all the work I have done. What should I do? Additionally, on the walls that look ready. I’ve gone over everything with a light and touched up the places I noticed. I’ve run my hand over the wall more times than I can count to make sure it’s smooth. However, I’m really worried that when I paint sections that aren’t level will be very apparent. Does anyone have any other tips to make sure everything is ready to prime and paint? Would priming the walls and then If anything comes through doing another coat be a terrible idea? It’s been a messy and time consuming process and really can’t wait for it to be over hahah Thankful for any advice!

We did veneer plaster for a couple of reasons. In our regional area, no one does it. We had to go to a specialty supplier and order it in. We found someone who trained in Maine to install it and the only reason it was a bit more expensive than drywall is because our original framing was uneven and we ordered 5/8" thick sheets. I had a pretty strong aversion to drywall after the adventures with mold. Veener plaster is freakin' gorgeous, perfectly smooth and we would do it again in a heartbeat. The feel of it perfectly matches the rest of the house - which is all 1920's plaster. Here, people call the supposedly water resistant drywall "blueboard", so I was surprised by what it looked like (gray, gray and more gray) and that it was made up of two slightly different layers and that it is much harder and denser than drywall. It works pretty well as a sound deadener too! @casey Wow, that is really nice!

My plasterer would use Durabond (20, 45, or 90 minute) for that project. If using veneer plaster like Uni-kal you would need a bonding agent (and you'd have to know what you are doing, ie fast).