On PCs, content controls have been available since Word 2007 (checkbox content controls from Word 2010). Content controls don't work at all on Mac Word 2011 & earlier (rather like PC Word 2003 & earlier) and, for Mac Word 2013, all content control development had to be done on a PC. Starting with Mac Word 2016, content controls can be added to a Word document. See: https://support.office.com/en-gb/art...8-CEC300136B82
Relatively few Mac users would be on Word 2016, though.

ActiveX controls have never worked on Macs.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]