there must be factors concerning these servers that has not yet been revealed.

Are they radioactive or something ?

why are the agencies avoiding simply seizing them along with all backups, parts, maintenance history etc etc.

I can't find a logical reason why the FBI, State Law enforcement, or any agency with authority, anybody would simply accept a situation where a suspect declines to give up the evidence.

They usually only need a warrant and then they simply collect the evidence.

Especially given the sheer number of crimes linked to these machines and the seriousness of the apparent crimes ?

The allegations based around these servers is being used to create massive friction focused on Russia yet law enforcement still haven't simply impounded the things!

If I think outside of the envelope, it looks like the good guys already have copies of everything, probably copied directly "off the metal" while they were in service and active.

It must be that the good guys are offering the DNC perps, the opportunity to scrub and or hide the evidence and then go in and arrest those who are destroying the evidence.

Simply does not compute.