You don't need to buy a dongle, it comes with bluetooth.

The problem with Keychron is that their bluetooth doesn't place nice with PC's. It's a wired keyboard at that point.

Not many low profile mx keyboards out there except for the Logi which I did own. It wasn't worth $180. My K5 SE was $95 or something shipped on sale. Your K3 is a MX Mechanical mini which is $150. Bluetooth works perfect on it.

I like the look/feel of the Keychrons better, despite having to plug it in.

Battery life on the Keychrons are dismal at best. Yes you'll be charging every week with the LEDs off. Not sure why Logi can design it where it goes months vs keychron days, but I guess that's what you get when you pay a couple bucks more.