Yes, I think we made some headway towards that goal in another thread: Conversation Flow - Inform 7 - #8 by StJohnLimbo
You can set arbitrary flags (truth states / booleans) when the player character or an NPC does or says something, and check those flags in the conversation rules. There are various ways to do that, but in the end it just comes down to a bunch of truth states and if-statements. You can also use the Scene mechanism, as shown in the linked post.
Another small example:
Mission-accomplished is a truth state that varies.
After asking Adam about "mission":
if mission-accomplished is true:
say "Adam gives you a thumbs-up sign and says, 'Good job on that mission!'";
otherwise:
say "Adam briefs you about the upcoming mission.";
And you would set mission-accomplished
to true at some appropriate place inside another action rule, like this:
After taking the secret document:
now mission-accomplished is true;
continue the action.