Stack? Are you saying you have more than one T8? If so use a little spacer/shim if you want. Some have a "milled/machined" groove to run your cord.. But i dont think you'll have a problem anyway.
As far as the Herpstat.. I see everyone running them like this, myself included...some of us run Herpstat 4's... with cords running everywhere like Highways hahahahah.
I think your good but maybe someone else has a opinion...