@_sotanaka Hm, this is however not the case in the 早引節用集 refered to earlier. Here it says instead: 光 くはう・かう・こう 香 かう・こう 〔中略〕 此類は両方を見るべし -- not very convenient for the casual user back then. ;-)
@_sotanaka Setsuyōshū are very interesting here. I've seen all possible variations: 1) both sections for え and ゑ (易林本等), 2) only え, whereas ゑ is there but empty (永代節用無尽蔵等), 3) only ゑ, whereas え is empty (大全早引節用集等).
(Pics from the latter @ https://t.co/9w0kSm4J7G) https://t.co/lSSzkb7yPF