How to build TZDateTime in ambiguous moments (DST transition)

[brinux]

This is just a question...

TZDateTime allows to set date-time and location to identify a specific moment in time, but there are ambiguous situations.
For example in Europe/Rome, on October 27th 2024 at 3:00am (CEST) time went back to 2:00am (CET), changing Zone (disabling DST).
Because of this, 2:30am is a valid time for both the new and the old Zone (CET/CEST).
tz.TZDateTime() allows me to set the location, which is enough 99.9% of the times, but not in this case...

// If I try to set the provided time...
final overlap = tz.TZDateTime(tz.getLocation("Europe/Rome"), 2024, 10, 27, 2, 30, 0);
// I get it in the most recent Zone (CET, no DST), after the time transition.
// If I want to get the previous one (CEST, DST), I have to manually remove the Save time (which is not straightforward to compute), applying DST.
final before = overlap.add(Duration(hours: -1));

Is there a way to create TZDateTime providing date, time, timezone and zone?
Is there a better/alternative way to handle this situation?

Thanks in advance!