[Bug] Soul Elytra Boost does not work in Trinket Cape slot

[twenty41]

Minecraft Version: 1.21
Mod Version: 9.0.0
Mod Loader: fabric 0.16.5

Description:
I use Trinkets and Elytra Slot, as I think tons and tons of people also do. So Elytras can be used in the cape slot, alongside chestplates.

The Soul Elytra works in this slot, but only as a normal Elytra. The boost hotkey does not work, and fills in with "Left Shift" though that also does nothing.

To Reproduce:
Steps to reproduce the behavior:
With Trinkets and Elytra slot, try boosting with the Soul Elytra

Screenshots:
In the chestplate slot:

In the Cape slot, via Elytra Slot mod:

Additional context:
If there is any way I could bridge this compatibility myself let me know. But I think this is a very common combination of mods that may be worth official compat

[NolanHewitt]

This would probably have to be fixed by the elytra slot mod. It works in the previous version of Deeper and Darker (1.2.6). Also duplicate of #335