Something I don't understand: Vivicca is clearly
a gerund (absolutive). Why then is it commonly
translated as if it's a participle (e.g. "secluded", "withdrawn")?
Such forms are common in Ukrainian and Russian, and they are called "adverbial participles". They are quite similar to participles.
Since there's no exactly corresponding form in English, someone called them "gerunds", which is rather a misnomer.
Let me link an explanation of their syntactical functions by Ven. Dhammanando:
https://dhammawheel.com/viewtopic.php?f=23&t=16316
https://dhammawheel.com/viewtopic.php?f=23&t=16316
With metta,
Dmytro
