Recirculating my BOV and turbo elbow Q

I’m planning to recirculate my blow off valve, are there any type of tee fittings that exist which I can put inline with my intake or do I have to weld a fitting/bung to accept the recirc line. The recirc bung on the intake should be the same size coming off the BOV recirc outlet correct?

Also, are the gains really noticable if I were to upgrade the turbo elbow. It only seems to make sense since the rest of the exhaust is 3". Also, should I be running a flex pipe to minimize the stress on the header? Sorry for the noob Qs, just trying to get the most out of my first turbo setup…

I’m no expert. Yet, to me. Sounds like you got it dead on.