Delta R10000 rough in question

As the title states I'm roughing in a Delta R10000 valve with the dryden thermostatic valve and trim. I'm putting it in the opposing wall from the shower head. The supplies are in but I have a question about the positioning of the valve. I've heard that the tub outlet provides more flow and in shower only applications, you should turn the valve upside down and use the tub outlet for the shower head. Then just install the cartridge backwards to make the positioning right again.

Is there any truth to this or should I just rough it in like usual and cap the tub outlet? And as for that, should I just cap it or put a drop leg in and then cap it?

The pressure balance Delta faucets that I used to install came with a plug
to cap the tub spout,for shower only.They could be used as tub & sower,tub only or shower only.Install the faucet with tub spout down. and cap it off.Hope this helps.

Thanks. That's what I thought. I'll keep the brass cap I have on it there. Is there any truth to the tub outlet having more flow? I suppose it doesn't matter with the flow restrictor in the showerhead anyway, I'm just curious.

The flow restictor in the shower head is the difference.