Yeah, but the scouter was unable to pick up the ki amplification. The blast is probably 322, just like Piccolo's power is. Raditz is shocked by ki amp and his scouter seems to pick up every discrepancy power so I can't say the evidence suggests Piccolo used ki amp here.
He definitely seems to be at full power because Goku is shocked at his ability to do so. He was legit scared of it previously, so I think that signifies a power up.
But is blocking a superior feat to punching something back? What happens if Raditz tries to punch back the blast?
So the best interpretation it's the same, but there is an inconsistenty. When Raditz scans Piccolo's power level, he calls it nothing compared to him. Yet, just a moment later he picks up Goku's power and calls it huge and than later on calls there power level exactly the same even knowing the tiny difference of 12 points and Flayk's blast which is almost identical to Piccolo's blast and destruction damaged/scarred an Oozura which is a 10x multiplier.
but they are likely low Class Saiyans but the random Oozura Saiyan should still have a power level of around 3000.
When they remove their weights their power level increases to over 400 and he laughses it of. It's a inconsistent mess.
To your point. Raditz was also terrified of a power level of 710. That's before knowing it was Gohan. So it couldn't because it's a young child with a Impossible power level to him.
But later on he took a headbutt from Gohan who had a power level of 1307 which caused his power level to drop and Goku's KKH is like 1000? And there is an argument characters such as Raditz and Nappa can't really hold back.
But punching a Ki attack away is definitely more impressive. As Piccolo, Zarbon and many threat it such.
Would you be more impressed by someone who blocks a boulder moving at high speed with his hand or someone punching the boulder away with punch?
