That lens is notoriously soft at closer focus distances though.
Not that there is really such a thing as a new formula these days; however there are levels of compromise for size, weight, distortions etc.
I have a X100T also and I never noticed "soft[ness] at closer focus distances," even with tele and wide lens attachments. However, I do see diffraction kicking-in at f/8. But hey, we all have different thresholds.