For those who still want to use the KS220M with Home Assistant, I have a partial workaround to avoid the crashing.

I say partial because it requires an internet connection, so the integration is no longer local.
I have added a Kasa integration into SmartThings, and then added SmartThings to Home Assistant.

Over the past month, I had 0 problems with this solution and KS220M dimmers.

As an added benefit, the constant network traffic to the Kasa device also stopped as there is no more polling.
I have not migrated the other Kasa devices to the SmartThings route (due to lack of time), but I do not expect any trouble from them.
 

  @ValentinMTL 

Hi chiming in here as well. 

I confirm that this has been working for me for the past 3 weeks.

Just make sure you "disable" the switches in home assistant under the tplink integration.

  @Wayne-TP Hi there. I also want to try the beta firmware on my 4 KS220M devices, hoping it will help. All 4 have the latest production firmware 1.1.6

I disabled them in HA, but they keep freezing.

Is there a way to automatically restart the device? If yes, I would like to try restarting it every night as a workaround.

  @AndreyPl 

You can automatically restart them using HA, but in my case, it did not help. I even had a 12h restart schedule and scheduled the polling to 10 seconds, and they would still freeze.

So far, the only solution is to disable the device in HA and use the integration from Smart Things.

For the beta firmware, you need to send @Wayne-TP a private message with the mac addresses of your dimmers.

  @GervaisdeM 

I disabled polling and the issue stopped. Unfortunately, otherwise it continues to be a problem. I have not had any issues since disabling polling. But there are obvious downsides to disabling polling.

  @AndreyPl 

Yeah just disable them in the tp link integration. And only using then via smarthings integration instead

  @AndreyPl 

Go to the tp link integration

Click on the 3 dotted vertical icon on the right