"where in the book is flaps 10 not approved to be used"

If you don't want me to use flaps 10, go ahead and make the stupid decision to ban its use in the book except for takeoff in the max. Until then, I will use flaps 10 when appropriate. Saves company fuel because the gear isn't hanging out for 20-30 miles creating all that drag( bet that would reverse the company decision real quick if they did try to outright ban the use of flaps 2 and 10).

Had a similar issue at my regional. Each CKP had their own interpretation of how to follow the book and some had machoism going on. Doing a fed ride with one of my students with the company approved CKP to act like a fed in the jump for their upgrade fed ride. Coming into the airport, winds were gusting around 40 knots. We had the performance to land using flaps 22 and thus chose that configuration for better Vfe margin and performance in case of windshear( also in my opinion, flaps 22 also resulted in less drastic changes in thrust settings). Land no issues, fed ride passed. The acting fed puts on his CKP hat on and goes, " You know the book says the preferred config is flaps 45 right?" We go, " yes sir" cause cooperate to graduate, etc but FFS it says preferred, not required or shall. We also had CKP that believed that if you couldn't maintain 15 knots from the adjusted approach speed to Vfe of flaps 45 you shouldn't be a pilot( where the machoism comes in). Sure should we be able to do it if we had to? Sure, but if the conditions to use 22 is possible, why not increase the margins?

Our approach profile at the regional was set up to intercept the GS at the FAF which was not real world realistic. At least our profile isn't that rigid( only recommended to go gear down flaps 15 at 1 dot or NLT 2000').......