I'd be surprised if anybody is going to let you drop a device into their internal LAN.
Back when I had the tolerance for stress to work on these, the client just wanted to be up, now. I think it just depends on the type of client we're discussing. If they're clients that outsource their IT, they won't know nor care- and I know this from personal experience.
That would be more the type we're discussing. Also these are MSP contract customers that want/need us to monitor various pieces of equipment on their network. We already have a strictly software based solution that we're using, but it needs to be on a machine that is always on so it can do its data collection and reporting. However (SOHO/SMB) users being users, they're continually shutting down, crashing, or infecting the machine in question - not to mention the software in question is a bit finicky - causing us to have to chase down why network X isn't reporting anymore. Because a data set that's more than 8 hours old...is useless.
So I'm looking to create a small, clean, stable environment that it can run from to keep both sides happy and trouble free.
The level of interaction with the client network is actually very low -(SNMP only - at my insistence)- but it needs to be for us to effectively maintain the level of service that we're offering.