I am doing a new toilet installation. The 4" waste pipe will drop from the toilet flange straight down a couple of feet, then through a 90 degree bend, then has a few feet of horizontal (on a slope of course!) run to the stack.

I have a 2" vent ready in the vicinity, and will connect the vent to the waste pipe with a 4x4x2 sanitary TEE.

Question: I could install the TEE either in the vertical drop pipe, above the bend, or immediately after the bend in the horizontal section of the waste pipe.

Is either one better? I think the vertical option is best, as it puts the entry of the vent air as close to the toilet as possible.

Many thanks for any advice!