There is a company local to…
There is a company local to me here in B.C. that remaps the ECU for just this reason.
I would do some research to see if someone like that is local to you.
Not a Yota owner personally but have had lots of clients and friends with them. Apparently it makes quite the difference on performance. I'd say for the MPG difference you're now seeing it's worth looking into.
FYI with the new ones you will find it shifting much more with the new added gears in the new transmission. A lot of customers aren't used to the new 8 to 10 speed transmissions, and not sure of one manufacturer that has not had issues with theirs (had to do recalls)