The technical details are just that - implementation details. Talk about features & benefits. How you do it is not relevant to a corporate development discussion.
There's no reason to allow that kind of detailed conversation to happen, especially not before figuring out what your stuff is worth to THEM.
They are clearly interested, play your cards carefully. There's very little to gain from oversharing, despite how hard they made try to persuade you otherwise.
Share strategicially. If you've already got credibility and traction and prototypes, demonstrating your competence can be "it works".