Mike Tomczyk from Dobinsons USA sent me this related reply today, after I inquired about progress on the 2" kit for TRD Pro suspension:
"It looks like we're backing off from the front coils and just sticking with the 1" front coil. There seemed to be a lot of interest early on in a 1" coil to add some height, but the sales haven't proven to be there, so with the extra R&D costs for taller and stronger coils (aka Air Freighting back and forth each sample set), we don't want to be working hard at it and not sell any/many at the end of the day. We're recommending people replace their pro struts all together and go with a new strut and coil combo, as we have a huge amount of options already for those and can tune it perfectly."