Looks good Archie.
You know the old saying about looking right & it'll fly right.
If your weather is any like it is here, you won't be testing it today

You're right about blow back. Had a Frantic in the mid 90's with basic (3001's) servos'. and that would roll faster downhill, on idle, than uphill.

Let us know how it goes when the weather gets better.

Ian.