I wish our culture was better at honestly expressing our level of uncertainty, and being okay and encouraging of other people doing the same. Having widely-understood ways to say "based on what I know now, I think X, but this is a preliminary opinion and I am super-willing to adjust based on new arguments or evidence".

I've seen ideas for conlangs that include a mandatory tense-like inflection for either "this is why I think what I'm saying" or "I think this with [high / medium / low] confidence".

Would be interesting to import into English.

Isn't the abbreviation "AFAIK" meant that?
In spanish we don't have that kind of abbreviation