Oh! I’m in complete agreement.
I’ve never heard of a vendor being so difficult. My comment applies only to interface errors. (Up/down status, rx/tx errors, fec issue, etc) Any vendor without an override for 3rd party sfp should be rejected after RFP.
If I report an IS-IS problem and the root cause is an OEM SFP on a completely unrelated port, then the design of the switch is pretty awful. :-)