Hi David,

I don't have access to the video on Google Drive, so I can't determine the exact nature of your delay. I requested access in the mail.

If you are using Aximmetry version 2023.3.2, then you won't have a delay parameter for the Digital Extension. Instead, it is determined by the Picture Delay set in the SELECT CAMERA panel:

If you don't set a Picture Delay and leave it at 0, the Digital Extension will fit nicely on your LED wall's image. However, the animation will differ between the LED wall's image and the Digital Extension's image (meaning the animations and virtual object movements will occur sooner in the Digital Extension, which you probably experienced as a delay). Additionally, switching between cameras will be out of sync.

If you set the correct Picture Delay, then animation and switching between cameras will be in sync. However, the Digital Extension Mixing will be less accurate.
If you render the Digital Extension separately as described here in the Multi-Machine paragraph: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#multi-machine 
Then the animation and switching between cameras will be in sync, and the Digital Extension Mixing will be accurate. However, you will need at least two machines and must set the delay between animations or events in the Flow Editor.

Note, in every scenario you also need to set the (AR) Tracking Delay, more on it here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#tracking-delay

Warmest regards,