While running the Batch Info Edit tool first gets you the Options window which lets to change the script eval expression before evaluating the possible results list, the Batch Rename tool always gets straight into evaluations which mean that if you made a mistake (for example, infinite loop) or have some heavy calculations set (for example, hash check with some additional operations) you are forced either to wait before making any changes to the expression either you have to reinstall the software because there's no way to break these calculations!
Could you please make these calculations in the background, time delayed, and re-updated as expressions get typed, without considerable workload? Or at least, to get that DiskTree tool "refresh icon" - which means that you have to press it in order to start the operations? No auto-start, please.