Could be imagining it, could be that the longer pipe is improving the flow velocity and/or stability of the intake flow.
I chased some performance issues when I went to pod filters on my '79 XS11 Special many years ago. Wound up discovering that the intake boots that came with my filters were blocking some of the metering ports on the filter side of the carbs:
https://caferiders.proboards.com/thr...special?page=4