I was browsing through all three editors (WiE, WaW, WWI) but I could not find any option to adapt the build limit (or while we`re at - also the morale of certain unit categories without actually upgrading them individually) via tech.
I`ve seen at least two custom campaigns (Fall Weiss, Empire of the Eagle) achieving this, but I can only find the description as of the localization.txt file but no other file nor editor option to mod the respective values.
May I assume the respective modders received help from the developers to do so or am I just too dumb to find the right spot to maintain those values?
Additional side question to the Hubert: Since supply is such a core element of the game and I noticed that one can put over-strength (experienced) HQs in the production/deployment queue (actually since SC2) and they seem to work nicely within the game mechanics (however I did not do any re-test after the more recent changes to the supply system). Did you ever think about the option to somehow allow this also within the game?
I would think this could fit nicely into scenarios where the overall supply level would be lower (Napoleonics, ACW). Since during that time supply would be a much more local topic, some commanders (& their staff) might be more fit to cope.
But then again judging some AARs, abstraction level and complexity of the supply system seem already a pretty good fit so a few players do excel at it, while still most others do not seem to feel lost completely. So even though it is always tempting to individualize historic commanders (rating, supply levels, no. of units attached, range of attached units), it is probably better to stick to the existing generic modelling (rating only, homogeneous max strength).