If you’re interested, I just did a major overhaul of my script notes on Bengali in Unicode. There’s a new section about which characters to use when there are multiple options (eg. RRA vs. DDA+nukta), and the page provides information about more characters from the Bengali block in Unicode (including those used in Bengali’s amazingly complicated currency notation prior to 1957).
In addition, this has all been squeezed into the latest look and feel for script notes pages.
The new page is at a new location. There is a redirect on the old page.
Hope it’s useful.