Thinset under Hardiboard and tile

I am laying Hardibacker cement board to a plywood sub floor and tile on top of that. There is 1/8 inch left over for thinset to make a perfect match to the hardwood floor it will match up to.
Is this enough? Can I get by with two thin layers of thinset for both layers in order to have a perfect match on transition?

Can I get by with two thin layers of thinset for both layers in order to have a perfect match on transition?

The thinset under the hardi will compress to about 1/16" thick, but under the tile, you will need enough thinset to achieve 85-90% coverage on the back of the tile (You strive for 100% coverage) but expect you will have 1/8 to 3/32" in thickness of thinset under the tile once set. You can't skimp thinset coverage in either place and a 1/8" difference in floor elevations won't even be noticed.

Thanks Bljack for your detailed reply.
I will do what you recommend and not worry about the slight hump - if any. Besides, it's difficult to get a true depth measurement with a piece of Hardi and tile just sitting there and I may actually have a little more than 1/8 inch anyway.
Thanks again for your advice. Much appreciated.