Reading the Manual "40/17;38/16;36/15;32/13 ~ 2.35:1 is written in it.

wand a lower low?, bike with a smaller wheel is the way ..

the 38:16 in my 26" wheel bike has a similar gear range in my Bike Friday (Pocket Llama , disc)

with a 53t & the 16t hub cog..

Thorn Sells a larger R'off cog to mate with a larger chainring so as to increase the wear life of them, just by being larger.. more teeth share the wear.
Thorn Sprocket for Rohloff Hubs - £29.99 19t x 2.35 = 44.65 so a 44 or 46 chainring would be good. *


Phil wood makes their version of the standard R'off cog sizes in a 1/32" wider 1/8" tooth vs the German 3/32" wide
"8 speed compatible" derailleur chain (which Rohloff also makes one)

* Given the appropriate chain line is typically where outer chainrings line up
& lots of MTB cranks have 44t outer chainrings , there is a bit of practicality there.