So; my take on things is this:
You’re getting better DPS with a pre-optimised set of gear and you know what Essences you want to use and in which slots.
Essences you don’t want considered can be excluded from BiB Optimisations; when it come to right & wrong you get into subjective territory, which is where I think AMR may be - as you would word it - ‘failing’.
Have you come to AMR to add advice to a pool for assimilation, or have you come to AMR to get support for what you believe to be an already optimal set-up, based on advice form another site?
If it’s the latter, then I don’t feel that AMR will serve you well, as you seem to have decided that advice that conflicts with what you’re already working with ‘will be wrong’.
The premise that any one optimisation/advice source is correct & others are not will always be a pointless exercise; sorry to say that, but all any site should set out as a mandate is a recommendation of what you should equip - only Blizzard can work with extremes of right & wrong and they don’t offer any services by way of gear optimisation, like AMR or others.
Now; having said all that, I open myself to misinterpreting how you have worded your queries and welcome better than myself - namely @yellowfive or @Swol - to re-interpret where I may have missed any points and further advise, accordingly.