P.S. (Can't edit above.) If that's a position you'll use a lot, you may want to reverse the neck and middle pups. That is, put the RWRP middle pup in the neck.
One of my guitars is three pickup with a tele bridge and two strat singles. I swapped the neck and middle pickups so that the RWRP was in the neck and then followed this wiring scheme and it works way better than the default strat wiring that came with the guitar.
Going through the switch positions you end up with:
mid
mid + neck
neck
neck + bridge
bridge
I just think of it as tele wiring with an extra two positions (mid, mid + neck).
I would just do this. Blender pot in place of the second tone pot is great, and it’s not just “on/off”, you can bring in just a little bit of the neck pickup, or the full level signal of the neck pickup. I haven’t done a Strat in awhile, but I used to do every one like that, and both of mine that I still have, have that setup and I really like it.