What if there was a civilization bonus that made Siege Workshop research much cheaper? Would that be overpowered?

I just look at the Burmese 50% Monk tech discount and wonder if a similar discount for the Siege Workshop would be overpowered or not. A SW tech discount would probably save you more resources than the Burmese bonus, but it'd only come into play in Imperial Age, while the Burmese can get some of theirs in Castle Age (especially important regarding Redemption and Atonement).

Would something like, say, a 30% discount be too strong?