SimpleTagProvider::updateValue - timestamp usage

I use a SimpleTagProvider to provide tags in a module.

Tag’s VQT can be updated with :

SimpleTagProvider::updateValue(tagPath, value, quality, timestamp)

How is used in Ignition the timestamp provided ?
Tag’s Lastchange property is updated according the current update date.

It will be usefull if the provided timestamp could update Lastchange tag property and the alarm timestamp if one alarm is configured on the tag.