I place a text block on my "Cover Page", which contains the "Designed and Installed By Electrical Contractor" Disclaimer, along with License number and expiry date, and two signature lines - one for the License Holder (my boss!) - listed as "President", and one for my signature - listed as "Designer".
I also include a basic stamp in the Title Block attached to each Plan Page.
It contains signature fields, designations (Prez or Designer) and License information (number + expiry date).
We both sign each page's Title Block stamp, and the Disclaimer Note Block on the cover page.
Had no problems with Plan Checkers doing things this way (began Designing Plansets back in the 1980's).
BTW, all signatures are "Wet Signed", on each set submitted (including "LTG-1-C" and "OLTG-1-C" Lighting Compliance Forms)