Does pureboot restricted boot record /boot files in TPM?

[amano]

Or, does it merely check that they are signed with librem key?

[FranklyFlawless]

Both questions answered in a related topic:

How PureBoot uses the TPM for trusted "boot measurements"

PureBoot should not complain as long as the private key signing the files is the same as what PureBoot is expecting. The TPM’s PCRs does not store measurements of hashes for partitions, at least with PureBoot.