Include ActiveX Command Button in Tab Order

In the attached spreadsheet, I am wanting to include the ActiveX buttons in the tab order when the sheet is protected. I would also like the ability to use the enter key to select each button when selected.

I understand that a userform or frame would have been a solution this issue, but that would require me to rework the existing code. I'm wondering if there is a VBA workaround with what I already have, so I don't have to start from scratch.

I have searched high and low, and this was the closest solution I could find:

https://www.mrexcel.com/forum/excel-...out-macro.html

The last comment on that thread seems to be the answer I am looking for, but the code is overly complex. Any help appreciated!!