Dont understand the issue .. have 2 hubs, both have 16t cogs. [QBP in USA only stocks that one for spares]

My '04 Koga WTR (26" wheel) came with a 130-39t crank .. replaced it with a M730 ; 110-38t..

other one is in a 20" wheel has a 53t chainring .. Bike Friday Pocket Llama. range pretty much the same..

moved from a hilly location, further down the hill, so not using the whole range , as before, in my commute.

AnyHow,
Quoting the Manual : To prevent overstraining the hub, a minimum sprocket ratio of 2.35 must be used.
15:36 16:38 17:40 anything bigger for a chainring is Fine..