An update on my flickering and Insteon communication issues:
For the flicker I ordered the inovelli. I did not care about any smart features for this particular switch. Unfortunately the flicker was just as bad, probly worse actually. I then installed the Zooz 800 Series Z-Wave dimmer, and it seems to have solved the issue. Again, no smart features used, just only as a dimmer switch
For the Insteon communication issue, I think I am still having very slow traffic, but the more remote KPL at my pool was very problematic, so I replace the switch with a Youlink dimmer. All is much better at least for the pool.