Ingredients missing from inventory and seemingly not in add-ons.

Example: White Labs San Diego Super Yeast WLP090.....I cannot find it anywhere in the database or on any add on. Is there any other database that has more add ons? If not, I assume the only thing to do is to add a custom yeast strain and use the website's blurb about it to describe it, right?

Yup that's what I had to do for wyeast pacman strain. All you need is the info on the website and you're off and running with your newly input ingredient.