(What model? I am a Denon user myself ;-)).

In principle, just try increasing one or both of the long delays ("0679") in the Pronto Hex code and see if it works. Exactly what the Denon accepts and do not accept probably no-one knows (and it may differ between models and possibly even among firmware versions).

To be more explicit: increase one or both of the "0679" and see if you achieve the desired result. Note that this is a four-digit hexadecimal number, so doubling it gives 0cf2, not 1358.

(Of course, you can also modify the IRP accordingly (increase one of both of 43.572) and re-render with IrScrutinizer/IrpTransmogrifier, but the result will be the same.)

Please tell us the outcome.