It doesn't really matter that the bag says shock. Around here we like to say "Shock is a verb not a noun". It's calcium hypochlorite and it's a sourece of chlorine like any other. It will raise CH but you've got plenty of headroom there.

You're right, bleach (Liquid Chlorine) is preferred as the chlorine source without side effects.

The CYA may be a little low - depends on shade, etc. You might want to bump it up if you find FC won't hold for a day.