You can't damage the amp with speakers rated at higher power.
You didn't speak directly to the technician, did you? There's nothing to support such a claim and I would disregard it. It must be a misunderstanding between technician and support guy.
As far as impedances go, there's no impedance matching for modern solid state amps (it's just pointless and expensive). If the amp says 8 ohms, that means plugging in a 4ohm speaker can overload it, which will sound nasty after certain power output. If it's got separate outputs for different speaker impedances than I would suspect current feedback and you would need to match the labels.
You didn't speak directly to the technician, did you? There's nothing to support such a claim and I would disregard it. It must be a misunderstanding between technician and support guy.
As far as impedances go, there's no impedance matching for modern solid state amps (it's just pointless and expensive). If the amp says 8 ohms, that means plugging in a 4ohm speaker can overload it, which will sound nasty after certain power output. If it's got separate outputs for different speaker impedances than I would suspect current feedback and you would need to match the labels.