I made this mistake, and I ended up with a grossly overpriced monitor which fails to charge a MacBook Pro and whose video through USBC support is hit-and-miss, in the sense that it doesn't always work.
I have no idea what led you to believe that someone searching for monitors that charge MacBook pros with thunderbolt did not checked if the monitor charged MacBook pros with thunderbolt.
though of course my laptop's intel GPU + mesa drivers tears drawing to the screen, but i generally don't care and don't watch video or play games on the laptop
And you can just swap between them by switching the active input source?
I do the same input switching he mentioned, and it works very reliably.
It also has support for pbp mode, where it can display each computer on a portion of the screen.
Currently I have a 34" 3440 x 1440, and with two separate docking stations (one for each laptop) and a USB hub for my peripherals that is connected to both docking stations. It's a lot of extra mess on my desk that ideally I would like to cleanup with having everything connect directly to the monitor.
BTW, how is the resolution on the 40"? Can you use it with native resolution, or do you have to do any scaling? Having all of that extra screen real estate would be awesome
For most peripherals, there are software solutions. I ditched any kind of KVM, and my monitor does not have USB ports. However, I use my monitor to switch inputs and use barrier to use the same keyboard and mouse on multiple systems (up to four). It works well and when traveling I also use it to work on my work laptop, with my personal laptop off to the side for reference materials, calendar etc.
KB/mouse -> switch -> desktop/monitor
Monitor <-> laptop (usb-c)
Desktop -> monitor (HDMI)
The downsides are that it only supports 45W charging, and you can't really use dual monitors.
Ideally I could use a KVM so everything is switched in one device. But USB switching is cheap and reliable (my switch cost $25 and has been rock solid), whereas the cheapest KVM I could find to do this cost $150, doesn't support 144hz, is stuck on hdmi 2.0, etc.
Depending on my needs I can run one of my computers using the full width, or run 2 at half width each.
This route doesn't have to be expensive either, my 1440p, 27 inch Philips docking monitor cost $270, basically the price of mediocre level docking station.