Are you familliar with Timme Rosencranz? http://www.jazzbaron.com/about-timme.html Timme had a good insight in the jazz world of the 1930's. In an article in a Swedish magazine about Lonnie Johnson he writes (if you can understand swedish see:https://www.digitpaul.se/veteranene-lonnie-johnson/) about when Johnson played with Fate Marable: "It was here that Bix Beiderbecke heard him and the two of them spent many nights together, Bix playing piano and Lonnie singing his blues while the boat slided forward on the moonlit river."
Sounds like a tale but it's worth noting.
You may have discussed Bix and guitar players before in the forum.
He seems to have been impressed with another guitar player from New Orleans, Snoozer Quinn, even prefered him to Eddie Lang. Snoozer was (probably) never recorded in his prime but on the tunes recorded just before he died by Johnny Wiggs he exposes a more down to earth swing style than the refined, classically ornamental one of Eddie.