Historian here, I have a source from the 18th century (1778) where a young nobleman from the north-easternmost edge of Europe on the frontier of the Russian Empire (today eastern Latvia) wanted to bring seeds from this Siberian Pea Tree (he simply called the plant "Siberian pea") to Italy, because there was interest in cultivating the plants for food there. Not clear from my source if he ever did get some seeds to Italy, but this suggests there is decent history of eating it at least close to its native range.
