What you really need is a small keypad with a tab key [in a useful spot]. I don’t think anyone makes that, but it sounds like what you need. One nice thing about DIY - you can choose the layout and keys that make sense for your workflow.

Remember there is no rule the says you only need one keyboard, or even that the keyboards have to be connected to the same window (I actually had it working once where I had two keyboards that went to different windows - but it was tricky to setup and not everything worked - in the end I didn’t find it useful but YMMV)