Possible to modify the ProjectionMatrix at runtime?

First post in this section so please go easy if I’m missing out on something here - quite new to modding the engine!

Prior to 4.14 you could access the FViewMatrices.ProjMatrix property directly and update it at runtime to give the view a different FoV.
Since 4.14 this has been removed and I want to modify my SceneView’s Projection matrix in the latest version 4.17 ideally.

I looked into the release notes for 4.14 and towards the bottom of these it states:
Try and avoid mutating the FViewMatrices and FSceneView on your own. It is currently practiced within the engine, but we would like to get rid of that.
It seems this is when direct public access to the FViewMatrices ProjMatrix was removed.

Does anyone know why this was implemented?
Is there another or a better way to access a view’s Projection Matrix?

I could really do with modifying the projection matrix dynamically at runtime and would really appreciate any help or pointers on how that’s possible…