I’m a big fan of using as simple of things possible to make an office setup, as I travel super light. It seems to me that your issue here is all about the keyboard.

I think the way I would do it is a tripod as you suggest. It will be the lightest, least volume way to give you guaranteed variable height control.

But I would buy a “shelf” that you can put the tripod on top of, and keyboard beneath.

Something like the below, if the top lays flat enough (I can’t tell from the photos). You’ll want to figure out a way to ensure the tripod is secure to it.

• BackPainHelp Posture Laptop Stand Desk Table Tray for Bed, Aluminium, Adjustable Portable Folding Standing Desk Computer Riser (Black) https://www.amazon.com/dp/B01BH7VV8Y/ref=cm_sw_r_cp_api_glt_fabc_5MA3BJGT9JHVKCF4XK15?_encoding=UTF8&psc=1

You could probably also have something fabricated pretty easily out of aluminum maybe. Basically an open box or shelf. It won’t take up much luggage space, and won’t weigh too much.