Assembly design using PTC Creo with Windchill

Hello, we have a problem in a company with workflow using PTC Creo and Windchill.

In attached assembly there is a mechanism of a theoretical machine. We want to be able to check for collision in different configurations during design process in different machine configurations. So we've created snapshots of those mechanisms using mechanical constratraints and checked in whole assembly. Since than there is no possibility to move with any parts at all. We can't activate any of snapshots while it's not checked out or continued. 

We need have to move mechanism during design process while it's checked in. 

For example we create new tool that will hang on paralelogram and during design process there is a huge need to always check if there are collisions and stuff around for safety purpose. Why we don't wont to use continue options and check out. those model are in it's final state and there are no changes needed to apply to them so data has to stay in it's initial shape before checking in new parts.