Location of shower panel over tub

We have installed a tub and getting ready to install a Hans-Grohe Interactive S II shower panel. This panel has tub spout. Our tub is an alcove (walls on three sides) installation. My question is about the placement of the shower panel. I am thinking of centering the panel over the tub (tub spout and the shower head directly over the tub drain/drain close lever). But my helper suggests installation a little off-center towards the wall. Any advice is appreciated.

Thanks,

Laxman

location

Normally you would center it over the tub's drain. Why would she/he want to offset it?