At least for some of my cartridges, the powder measure needs the full ram travel to fully activate, requiring that the die be kept close to the shell holder, switching expander plugs.
If you understood how the Lee expander die actually worked to activate a Lee powder measure, you would not make such statements as that.
How close to or far away the die is to the shell holder is completely and totally meaningless. The issue is for the floating plug to reach its maximum height at the top of the ram stroke. The powder measure is activated by the case pushing up on the floating expander plug, so you will
always have full activation from any case that is
at least as long as the caliber for which the die was made. The only limitation for loading longer cases is if you have enough room to back out the die far enough to accommodate the longer case. And THAT is why you buy the .38Spl dies to load Special, Magnum, and Maximum in the same caliber.
Now if your problems is that you bought the .357Mag dies and you cannot properly load .38Spl with them, well, you are trying to do something that was never intended. That mistake is yours, so don't blame that on Lee or their dies, and don't tell a new reloader they will have to buy more parts unless you clarify that you are telling them how you fixed a stupid buying decision. Furthermore, even if you found a way to work around the proper activation of a powder measure, you still would not be able to properly crimp a shorter case with the .357Mag dies unless you ground off the bottom of the die to make it the same length (or shorter) as a .38Spl crimping die.
I will also note that while most Lee pistol die set instructions are not caliber specific, their web site clearly states that to load .357Mag with the .38Spl dies, you need to "back out the Powder Thru Expander Die, and the Bullet Seating and Crimping Die about 2 turns to compensate for the longer 357 case." Furthermore, they clearly state that you cannot load .38Spl with the .357Mag dies.