I never used clamshell mode before with my laptops until recently. I always like the simplicity of using the built in keyboard and screen.
However with my most recent work the laptop is too hot to use directly due to it being top of the line. This isn’t to brag, but rather state that when you get a top of the line machine expect to feel more heat.
Since it was so hot I couldn’t put it next to my personal laptop on my desk. I work in a room with a South facing window and even with AC the heat would be too much. I had to reconfigure my desk and rethink things based on airflow and cooling.
Now I am in a situation that I like. One of the interesting things for me is that I use the work computer in clamshell mode with the screen projected to my big screen, and I use the personal laptop right in front of me. The work computer I use the wired keyboard/mouse and it works really well.
I have tried keyboards that let you change the input but those are awkward and a high cost. I also don’t like having to recharge them. So I am not doing that again. I don’t want to get a KVM switch either. That is a pain too. I hate cords. So this setup works.
During the day my personal laptop isn’t in clamshell mode and I can use it to learn things that help me do my job better. However when I am done for the day, I close the lid to my personal laptop, and switch the video source with one button on the remote and I see my personal computer video on the large screen. I use Voice Typing to control any keyboard things that I need, and it works really well.
Perhaps this might work for you?