https://wiki.fractalaudio.com/wiki/index.php?title=Firmware_release_notes_-_Axe-Fx_IIII may have missed this, but did this delay block update come with 16.05?
16.03 release notes say:
* Improved Delay block algorithms and models. Improved menus by adding a basic Config page with the essential controls and an Advanced page with all the controls for that model. Added a Master Time control.