i've read here that "Ignite Express" is not compatible with Magix's "Video Deluxe".
So is "Ignite Pro 4" compatible?
And are the "Add-Ons" only available for HitFilm Express/Pro?
No version of Ignite is compatible with Magix Video Deluxe.
The "Add-ons" are only for Hitfilm Express.
@Triem23 is correct, as far as the full Ignite products go. Ignite Pro does not support Magix Video Deluxe as a host.
However, Magix does offer some small collections of plugins specifically for use in Video Deluxe, which are based on the Ignite plugins. Those plugin packs are only available from Magix directly.