Is this substrate ok?

[Boggs]

Probably not if it’s a cut edge, I didn’t see that originally.
I think I would use the Schlüter trim especially as there is a slight difference between floor heights.

 

[Waluigi]

I’ve not seen that Schlüter trim before. Looks perfect for this instance. Not sure how it would accommodate different height floors though. If indeed they are slightly different heights. The photo is deceiving.

 

[Time's Ran Out]

Really something to decide before the final edge tile!

 

[Perry]

Rub the cut edge with a bit of glass paper then Silicon.