Text events from imported workouts (via TP) show the underlying message not the individual messages at the specific time.
Testing was done with the TPV workout "Aerobic Ride(30 mins)".
I created a group workout and joined it solo.

Imported from TP the text event looks like this in the log:
[9/3/2026 14:51:01.761] Received UI main message: !TextEvents:{
10:Welcome to Aerobic Ride;
20:This classic workout is perfect to recruit slow-twitch endurance muscle fibres.;
30:Alternating 5 minute blocks of
Zone 2 and Zone 3 throughout.;
60:For now, focus on warming up, and getting your legs spinning.;
150:Half way through the warmup.;
240:1 minute to go.;
}

Using the built in workout from TPV the log looks like this:
[11/3/2026 09:38:10.297] Received UI main message: Welcome to Aerobic Ride
[11/3/2026 09:38:20.296] Received UI main message: This classic workout is perfect to recruit slow-twitch endurance muscle fibres.
[11/3/2026 09:38:30.285] Received UI main message: Alternating 5 minute blocks of
Zone 2 and Zone 3 throughout.

This behavior is identical with self-created workouts imported from ZWO format.