The idea of using reduced size targets to "simulate" ranges is a long proven technique.
However, the idea is to this technique to improve shooter's mechanics, not to improve the shooter's skill in come-ups, wind estimation/compensation.
If a shooter does not have proper mechanics, they will just be frustrated at actual distance shooting. If they have the proper mechanics, they will be able to much more easily learn and apply the skills needed at actual distance.
Point being, if you can not do it at reduced sized targets at reduced ranges, you can not do it at actual distance.