I just can't imagine that the MT4 has a larger following than the Futaba 4PL does. We have one MT4 used at out track compared to easily 15 to 20 4PL's that are at our track. I would just think that the 4PL for the money is one of the best mid priced radios by far.
There are more dealers selling Futaba than Sanwa for sure, thus the larger group of 4PL owners.
The difference is the demand for a drop down came from the MT4 owners first. We have talked to 4PL owners a year ago and they felt it was not needed or else they would have bought the 4PKS that supported a drop down.
As for the MT4 owners, the M12 was not out at the time and the M11X was considered very heavy.
The deciding factor for us to produce a drop down for the 4PL is if it can actually sell. One of the problems with the MT4 drop down project a year ago was only a dozen owners were willing to commit but for us it can not justify the production cost to do a dozen.
So if the 4PL owners, say is 20 times that of the MT4, then mathematically the demand should be the same. A drop down is a preference upgrade not needed by most non racers. The 4PL is currently used by the masses and not hard core racers.