Have you thought about having one machine plus a hot spare, and swapping out hard drives? If it gets subpoenaed for job X, put the job X drive in and give it to the lawyers, then put the drive for the current job in the spare, order a new spare, and carry on.

Of course, if you can bill the machines through to the clients, why bother!

swapping out hard drives in modern laptops sounds like an easier time for you? even w nvme sticks im gunna go with "no way"

with linux? i swap hard drives all the time

With whatever OS you like.

Good luck switching hard drives on locked down customer provided laptops, or from the own IT on the consulting firm for that matter.

no, not whatever OS you like. Windows installations are coded against doing this. You can copy your Windows partition to a new disk and insert that, carefully, but you can't plug it into a different motherboard.

but you can with Linux.

I've never tried it with MacOS but the days of swapping Apple harddrives are in the past anyway.

You don't even have to open up the laptop anymore with pcie pass through on thunderbolt/usb4, you can attach NVMe physically externally without the typical USB IO hit. That gets into a discussion of enough ports and docks and what not but it is possible and in many cases pretty easy. Of course, that tends to cost extra as that tech isn't ubiquitous yet, but it's cheaper than a separate laptop.

Now, if you're doing this for concerns regarding discovery, I'd just use separate devices, as my confidence is low the court wouldn't just require the entire host(s) involved anyway.

This is personally why my environment is not tied to a specific host. Should any given device(s) get caught up in discovery I can still build/recover a full fresh environment on a new device relatively unimpeded - and do so regularly to ensure it's not just a theoretical. It can be a hassle, but at least I'm not trying to juggle devices in that way and have flexibility to either BYOB or work with client supplied kit and still bring my env and tools with me.