You do not have to temperature cure between XTC Primer and XTC.
You can do the temperature curing as described in the XTC Directions after you have applied both XTC Primer and then XTC with the appropriate time between coats based upon whether you are using the aerosol or the non-aerosol.
If you have already temperature cured XTC Primer, you are free to apply XTC and then do the temperature cure for the XTC.
Please be sure to review the XTC Complete Directions and XTC Primer Complete Directions before you begin your project.