Now, I love Olights overall and have had no issues with them, but I don't know that I'd have one on a carry gun if that's what you are looking to do. For me, for a carry gun I'd at least look at a Streamlight. But that's just me.
Anyway, holsters for guns with lights usually index off the light so you might try to find holsters for the Olight and then get dimensions to see if the EC will fit. The EC has been out long enough that there should be holsters out there for this.
https://legacyfirearmsco.com/shop-by-mo ... -holsters/
https://www.canikusa.com/canik-light-be ... ck-holster