In the Tahi, true ‘v’ is replaced with ว. Also, the Thai rigor of pāḷi chanting insists on their particular ephony of retroflex consonents such as ṭ & ṇ, of which is rather hard to render any transliteration.
When I was chanting with the Lao saṅgha it was difficult to follow after training with the Thai, as they chant pāḷi according to the custom of Lao language. Lao does not use ‘r’ or ‘ch’ giving brahmacariya the euphony boomasara.
And as retro has mentioned, the Sri Lanka saṅgha does not seem to care. Although a Sri Lankan abbot I stayed with mentioned that there were some variations in the pāḷi texts where the 'v' is found replaced by 'b'.
Fingers walk the darkness down
Mind is on the midnight
Gather up the gold you've found
You fool, it's only moonlight.
If you try to take it home
Your hands will turn to butter
You better leave this dream alone
Try to find another. – Townes Van Zandt ‘Lungs’Secure your own mask before assisting others
. – NORTHWEST AIRLINES (Pre-Flight Instruction)A Handful of Leaves