Vivaro shower ride height in parking garages

Hello, I am a service technician of profession and have a Vivaro A as a long version. This has a front disc sticker with a minimum shower height of 2.3 (with roof antenna), the car itself is according to type approval 1.96m high. Professionally I often have to work in inner cities and there it is often the case that the parking garages are only 2 m or even 1.9m high. Parking garages with 2.1m have already driven without problems, but go 2m also? What does it mean if 2m are signposted, is t the guaranteed so with still 10cm reserve, or does that mean that from 2.01m already the roof has a bump? Thanks already for your help.