True, I do not like productivity module for giving extra resources from nearly-free energy. It is unrealistically too good.
And I hate spamming beacons even more. (Someone wrote mods about that, overlapping beacons will overload and stop machines in the area. So only one beacon max on a machine at a time.)
But then it is the problem on modules and beacons, NOT related to the scaling factor.
If you limit yourself not to use (or only a few) beacons, then there is not a problem at all. It is a matter of self-discipline.
Maybe I can add an option to disallow module effects in some future, but I cannot promise as I never tried that and do not know how that may work.
But again this is a matter of self-discipline, user can still opt out of the option.
(The primary purpose of this mod is just "merging" multiple entities in a single scaled-up entity, without non-essential modifications. So such extra limitation will never be forcefully applied.)
The scaling factor of 4 is based on the setting of machine tier +(n+1) is exactly four machines tier +n. It is like a fundamental property and there is not much to change.
Scaling factor of less than 1 or even 1 does not make sense. Why should I provide such "high tier" machines if they are not better than their basic ones?
For such a narrow valid range, I do not think it worth the trouble to allow freely set the scaling factor. Especially, the problem lies in the modules and beacons, not here.