no dv will mean slightly slower re-spool through the gears (probably unnoticeable on 8psi) and wastegate chatter which I personally like the sound of. Depending on the turbo, 8psi and no dump valve will probably do no harm whatsoever, depending on it's thrust bearing design.
Fitting a recirculating dv is probably your best option - you can keep it fairly quiet that way, and benefit from keeping spool times as low as possible (have the recirc outlet as close to the compressor housing as possible).
I've never seen a turbo fail (or heard of a turbo failing) as a direct consequence of having no dump valve fitted.
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