I think you'd have to replace the chassis door to change the style of blinds, as it looks like the pillar dividng the side windows is a permanent Sprinter door fixture. That said, I think you're going to be out of luck find an easy fix for your problem.
However, I'm no expert, and so will just watch the thread.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)