Yeah, the change from a fluid resistance to ERG control is a different feel for sure. I spent many years honing ERG use on real flywheel trainers.
CycleOps Powerbeam Pro > my first Hammer > Kickr17 > H2 > Neo 2
Other than the slight change in feel, ERG use on the virtual flywheel of the Neo 2 was an easy transition after years of prior ERG use.
The K18 you rode is very close to the feel of the Hammer trainers. I suspect that you just need to spend more time and get used to ERG in general. Sounds like you already have the right idea to focus on power and cadence.
Just make sure to be as smooth and steady as possible, and that will reduce the app and trainer intervention to change resistance.
I was just talking with a training partner during a workout last night. He was complaining about the feel difference inside on ERG vs outside. He prefers the subtle changes in power outside vs the more constant loading in ERG. He has been using my H2 lately, but has used all my trainers at some point.
So, I told him to try Resistance mode (or Standard for some trainers) on the next workout. Essentially his comments are kind of related to yours. It gets to the fact that some people really like ERG and others not so much.
I do mostly ERG, but still do Resistance for some workouts (like Baxter and some harder sprint workouts).
The nice thing about a smart controlled trainer is the ability to use either mode that is preferred on a given day or workout.
All that goes to say that I think you can work with any of the trainers and the slight differences aren’t probably enough to matter for ERG use.