Replying to Mounting Chronics centered or???

So i got my chronics in and im stoked!

Im still in doubt were im going to mount em.

Im leaning to wards center mounting them..

Ive read that +2 is a good one too (is that +2 from where it says midsole?)

Ill mainly be riding indoor park with them like 90%.

This is the first time im getting skis mounted and i dont want the shop to mess it all up.

What should i do to prevent that.

Thanks alot ++ K