> I printed this out of carbon fiber ASA, but probably boring old PLA would have worked just fine.
I doubt it: PLA begins to soften at as low as 55 degrees Celsius. If there's weight on it, it's worse: the piece shall quickly deform and become unfit for its purpose.
This rig looks like it means business: I think PLA would fail.
If, like me, you cannot print ASA (say because you've got a printer that is not closed and that won't heat enough), then PETG-CF (PETG reinforced with some carbon fiber: it's got better heat deflection than plain PETG) is a safer bet than PLA for parts to put in PCs/servers/rack. Moreover PETG-CF do look really good.
The fan shrouds likely would have been fine. The hot spot on electronics is generally very localised to the chips and drops off sharply as you get further from them. I've printed a 10" home server rack out of PLA which is warm and under constant load, and it's been running for around a year now with no deformation.
A good rule of thumb is if touching it would cause burns, it's too hot for PLA, otherwise it's likely ok.