I posted about something similar, a way I guess you can do it is speedrun through the first playthrough, the world record is just over 2 hours lol

I think its a silly decision to make the ability to upgrade weapons and shields, a hard mode and over small but quite important features only for NG+, would love to be able to have those features but on a first play through, honestly dont think I could bare one play through going as quick as I can through the story just so I can get to NG+ to play with all intended features. I guess this can be done with a NG+ save file but since other things carry over like gil and schemata it isnt really a fresh save. Thanks in advance.