I was wondering if there were plans to allow the installation of Incus OS on hardware without TPM.
The use case is salvaging old R630s (ordered without TPM back then) and use them as low-stake compute pool. I’m not out of options to get Incus on there. But beyond its security guarantees, IncusOS sure is convenient.
There are plans. Here is the GitHub issue.
Looks like sourcing TPM 2.0 modules for DELL R630 is a PITA from what I could find, quite different from the experience I’ve had with SuperMicro, Asus and some other brands where you can find the modules for 20$ on Amazon with next business day delivery 
The swtpm should be able to handle your use case, you’ll just have to plan having a USB stick in each of them (maybe they have an internal header for that) with a drive that’s been prepared ahead of time with the correct partition label and anything else we may require for that.
As mentioned, the machine will be marked as running on a swtpm (likely as the TPM vendor) but that should be about the only difference from the real thing.
I was trying to source them for R730’s and it was mostly misses on eBay. They were used and locked to another server. Some did work. Weren’t expensive at the time. They were $70 US new from Dell at one point but they stopped supplying them.. maybe was a problem with Dell in our region.
Looks like sourcing TPM 2.0 modules for DELL R630 is a PITA from what I could find
Indeed. They supposedly never sold separate modules (it had to be fitted just before shipping) so I guess this explains that and they probably did something silly to ensure that getting cheap knock-offs wouldn’t be trivial.
you’ll just have to plan having a USB stick in each of them (maybe they have an internal header for that)
Certainly sounds good to me!
the machine will be marked as running on a swtpm
That would be absolutely perfect indeed.
They were $70 US new from Dell at one point
The doc for the R630s clearly states that the modules are meant to be factory-fitted. Their being modular was mostly for repair purposes from what I gathered. But hey, that was a long time ago, things might have changed multiple times since.
That rings a bell actually and think it was mentioned on a call with a reseller or Dell themselves, but I clearly remember the $70 quote for a new one because we got a $42 000/year quote from a cloud provider at the time for another site which was a joke.
It must be that if one has to have the right spec machine from the factory by chance which allows you to add in later. We got a bunch of used second-hand TPMs from eBay in our R730’s ($8.66 US each) and some worked, and others didn’t, purely down to previous usage. We knew of the risk but it was worth it. The seller organised alternatives.
So yeah, this could still be a PITA even if by luck the R630s will take a TPM module.