Test text:
ওহে বিশ্ব!
Glyph indexes (allsorts):
1497 1530 1539 3 1521 1533 1527 1543 1521 4

Glyph indexes (rustybuzz):
1497 1539 1530 3 1533 1521 1527 1543 1521 4

We can see there's a bit off with allsorts.
Used config:
let script = tag::BENG;
let dir = TextDirection::LeftToRight;
let lang = Some(tag::BENG);