Sensitivity Label autodiscovery and encryption eDiscovery on an E3/E5 hybrid tenant

Question

Good day,

I have two questions around a tenant in which a part of the userbase has an E3 license and another part an E5 license.

1: If E5 Sensitivity Labeling Autodiscovery is deployed, will the two user groups get a different experience (where autodiscovery simply doesn't work for the E3 users)?
2: For eDiscovery content outside of Exchange (like on SharePoint) that is encrypted will not be scanned unless you use Advanced eDiscovery (an E5 feature). Should we wish to fully investigate an E3 user's encrypted content, is it sufficient to elevate the account to an E5 license before starting the scan? Or will all data historically encrypted while the account had an E3 license be out of reach?

Thank you for your time.