At least when using ProType Titler, if you start with the default event length of ten seconds, perform some automation and then extend the event by entering a new time or using the "Match event length" button, the automation will scale to the new time, so the keyframes will not be in the same exact place they used to be.

Is there a way to avoid this behavior? I tried to find a setting in the preferences and I couldn't. If I remember this correctly, this is not the default behavior when extending events that have automated effects in them, in that case the keyframes stay in place and you have to extend them yourself.