No — you do not have to temperature cure between XTC Primer and XTC. You can apply both products and do a single temperature cure at the end.
Apply XTC Primer first, then XTC, following the appropriate recoat window based on whether you are using the aerosol or non-aerosol formula. Then complete the temperature cure as described in the XTC Directions.
If you have already temperature cured XTC Primer, simply apply XTC over it and perform the temperature cure for the XTC at that point.