Only BiS I focus on is DoL/H and pentameld it.

For DoM/W I usually make myself the highest crafted version, I don't even run experts cause the gear is useless for me.
The only time this expansion I focused on Lv90/Expert roulette was for the relic, once.

My thought is, unless you're doing savages and high-end raids, don't bother getting BiS. But, if you want it, you do you. We're not paying for your sub.