I've made 3 crosses full brother x sister and produced 3 pretty good dogs. Just dont be suprised if you pull some skeletons out the closet!
LOL remember you're doubling up on everything good & bad I got several with underbites , pink nosed & palefaced, shaggy coats, weak voices ! I will say everyone I raised had plenty of sense none were crazy the first 1 I raised when we carried him to the woods we seen a track turn him out and found him bayed alone he had plenty bottom & hunt! He was so ugly I carried him to the woods in a tote sack LOL We called him Rag if that tells you anything
We just didnt have any options at the time as far as Good solid unrelated yellow dogs to breed to! I didn't know what to think until I got online and talk to some older BMC men like Skoalbandit, BigO, Ray Modisette , and found out they also get some thick coats ,pale faces and such . I will say I have a couple 5month SireXDaughter cross pups right now that I'm enjoying watch bay and work everything that moves LOL
As a kid I raised some nice 1/2 sibling cross beagles that were top notch rabbit dogs ! Anyway that's just my little bit of experience!