Custom Activity should show datetime data in user's timezone

Recently I found out that datetime fields in custom activities are displayed in US Central time.

This is what customer support said:

Whilst activity timestamps adjust based on the timezones set on the Marketo instance, the information inside activity details do not support date-time localisation. These only return raw data for field values in those activities.

UTC is ok but US Central is a bit of confusion for me as I live in New Zealand.

Ideally I think it should show timestamp in user's configured timezone.

If it's too difficult, I'd rather see them in UTC.