VRSF makes a 3.5" DP.
https://www.xbimmers.com/forums/show....php?t=1385900
https://www.xbimmers.com/forums/show....php?t=1014191
The OP is getting the Speedtech Stage 3 turbo upgrade. A DP is included in the package. If you are going that route (upgraded turbo), save the money and get the DP with the package.
The instructions for the 535 should be the same or very similar for the E70.
https://f10.5post.com/forums/showthread.php?t=1296547
No aftermarket IC for the E70 currently as far as I know.