Actually, you can do that particular one. Location mode is allowed to be a pre-condition to any others. You can also change the conditions from All (and) to Any (or). So you end up with:
If Location mode=somestate
One routine I have is “If either sensor is present, unlock the front door, change location mode, disarm security, send a notification of disarming”
Also, you have greater flexibility in some of the SmartApps like LUM where you can prevent certain things from happening based on location mode, presence sensor state, etc. In fact, LUM treats the Life360 presence sensor as part of “People” just like a mobile phone presence.