I don't know of a way to add a check box to the title block. That said, you could create a custom properties template that has a check box and that could link to EPDM. From here, you could display the text value of "checked" or "unchecked" in your drawing template. Not ideal.. I get it. The only other way to do what you are asking is through a custom api or possibly a macro.
Thanks for you help! I did not think of just using "yes" and "no" in the drawing, but of course this makes sense as there are no checkbox feature for use in drawings in SolidWorks. If I'm not mistaken it is also possible have the EPDM checkbox mapped to the property in the title block and have it displayed "Yes" and "No" instead of "1" and "0", but I've heard the Yes/No variables are somewhat unreliable!