Lifting my 3rd gen

I'm doing as much research as I can on lifting one of these. I've been lifting trucks since the early 80's. My last project was a JK that I just sold year before last. My question is......I don't see anyone offering a duel rate coilover for these trucks. I had duel rate coils on the JK and it rode awesome. I see that duel rate coilovers are available for the new JL ( including Gladiator) that have coilovers on them (not all do). Why isn't someone offering that for Tacoma? Or am I just not finding it?
They even offer rear duel rate coils for the rear on 4Runner.

 

It's because of the IFS. Dobinsons tried a dual rate coil up front, but the high spring rate required (550-600lbf/in) makes it just not work well. With straight axles it's straight forward, like the rear of a 4Runner, but no one bothers up front.