Yes this was somewhat common in the old days with model T Fords etc. I believe it was still done on a regular basis up until the 1960's for underpowered cars and trucks that the owners wished to overload instead of buying a big enough one for the job in the first place. This type of thing died out in the late 60's and early 70's when powerful V8 engines became commonplace. There are still a few double transmission "twin stick" class 8 trucks in use. There are even a few die hards who convert newer trucks to this abomination. I cannot imagine why anyone would use something like this when there are better choices available.
Oh, sorry, silly me, I temporarily forgot who I am talking to, A bunch of Subaru fans.
My Subaru is as stock as the day it left the factory, and I still love it! It even still has most of the original parts! I wish the air conditioning did not cost so much to fix, then it would be perfect.
Bill the Truckerman