Pacing zones: auto-update?

Returning to running after a couple of years out, easing into it with a Zwift Run training plan.

Went into my profile which had all my IRL PB’s (must have previously entered them) but which are now way off my current (non-) fitness. So I removed them all, entered a 5km time from an effort last weekend, and accepted all the other blue suggestions (seemed to be sensible scalings from what I entered).

Now I’ve started my plan, and start to regain some fitness (hopefully!), is there some sort of cleverness that constantly evaluates my performance and updates these? Or will the plan carry on working to these until I manually change them OR it see’s a PB set on the treadmill over a specific distance?

Struggling to get my head around how this could work as obviously you run at the specified speed - while I get if you are struggling you could nudge the speed down, if you are doing fine then you aren’t going to nudge the speed up. Unless the relationship to / trending of heart rate is being monitored too?

It’ll update alongside your 5km time - if that gets quicker the intervals will get harder.

If you are finding that the segments are too easy or too difficult you can adjust the bias up and down which will greatly assist you.