Power of Inoue's kind can't translate as he moves up, especially this fast. He was touching guys at 118 and they were hurt. He is hurting 122 champions but it is taking more shots now to stop bigger more durable champions who have few if no defeats.
There were fights in lower weight classes whom he stopped with accumulation of damage (the Kokietgym's were stopped in round 11 & round 10 respectively, Dipaen in 8, Paul Butler in 11) or even failed to stop (e. g. Taguchi) Tapales weighed 139.9 lbs on fight day vs 135.4 lbs for Inoue & the data @Serge shared suggests that most Feathweights rehydrate to high 130's or 140 so in terms of power he should be able to handle most of them except the biggest guys like Otabek & Espinoza who will be 140+ come fight night
I think Inoue could put on some functional muscle and really crack at FW. He's lean as a bean at 122. Sure he'd be outsized by some at 130 but only elite boxers have a chance of victory or the most durable rehydrators. I can see him doing a pac-marg performance but he'd have to fight super disciplined against the shot pickers who are naturally bigger. Footwork and positioning would be key and he's exemplar at both.
I just remembered Leigh Wood's comment after he sparred Inoue to help him prepare for Jamie McDonnell who was his first fight at 118 https://www.youtube.com/shorts/SrdeITNjD8o Wood in the above video said at that time that Inoue could carry his power up to 126 & may be even 130 & Wood was a big guy for 126 which is why he moved up to 130 after Warrington
He will have a tougher time with much taller fighters, but still wins. I think he becomes undisputed at 126. His real challenge will be at 130, but i think he goes undisputed there too and retires at 35 like he said he would.