I use a ConnectPRO UD-14+KIT, 4-Port DVI+USB DDM KVM Switch:

https://connectpro.com/products/ud-14-dvi-d-kvm-switch-for-one-monitor-and-four-computers

It supports four machines, but I use it with either 2 or 3. It works well, I have no complaints

It’s possible to have only one earphone working if the connector is not pushed all the way into the jack.

I used to be overweight, but lost 25 pounds and I find that heat and humidity bother me much less than before. The other thing that helps is loose fitting linen clothing and wearing boxers instead of briefs.

Tankie is a pejorative label for communists : https://en.wikipedia.org/wiki/Tankie