Customising Freestyle or a custom edge shader

Hi guys, I’ve just discovered Freestyle for adding lines to an object.

My problem is, as you can see in the video, is that when the camera moves around certain angles, the lines disappear. Is there any way to set this that they’re constantly there in certain areas, or does this require a separate shader?

Keep an eye on the bigger box section to the right and you’ll see lines appearing and disappearing.

I know that in Cycles I can activate the Cryptomatte, select my object, do a little dilate/erode math with the alpha channel and then get a single outline, but I want to do this in EEVEE. I can’t even get even get a single objects alpha channel to appear in EEVEE.

Am I missing something here?

EDIT: I guess I can use layers and do it in the comp that way. Still, I’d love to have it all in one layer be able to use the Cryptomatte.

EDIT 2: When I use layers, how do I turn off the background colour for the foreground layer, but leave it on for the background layer?