so the current or highest attack a blue weapon will do is 294. but in the next "expansion" blues will become over 300 atk.
and unless VoG wont be updating its hardmode to 32 or something the new blue weapons will be viable in VoG.
[spoiler]just thinking it right now. also ill let this sink in[/spoiler]
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Current blue weapons are viable too. The 294 ones you mention are more then enough but they have less perks.