_coerceFromString not called for value sent in ON_CHANGING event

I have a scenario, when Textbox input sent to server needs to always be encrypted.

I overrided client methods coerceToString_ and coerceFromString_ expecting data exchanged with the server always goes through these methods.

While it is generally true, I have found one scenario where it doesn't work.

Data sent in ON_CHANGING event is raw data from Textbox component and the coerceFromString is not called.