Turns out, your best bet is probably to encourage your community to use a new standard. You could help them by creating a topic template in the category setting.
Aside from the backslash a couple other options:
Code blocks
Use three backticks ``` in a single line before and after the dialogue.
- Hello, how are you?
- I’m pretty good, thanks.
Use two dashes
-- Hello, how are you?
– Hello, how are you?
-- I’m pretty good, thanks.
– I’m pretty good, thanks.