I am certain I am not following everything your saying, but you might consider making elbows (call them bends) with the same connectivity as your weld joint; this way it can direct connect with pipe.

Create a Bend ITM and set it to 10° with optional angle tolerance of 10° and make sure you don't have a competing elbow within that range using the same button code and it should be used for anything between 0° and 20°. Maybe you only want this to happen in very small angles though? In that case you would just reducer base angle & tolerance settings.

Note:

You may need to make one side of the elbow a connectivity that would add a weld and the other that wouldn't, but having bends/elbows for all various degrees (with no overlap within tolerances) is the only way I can think to simulate a bend instead of a welded fitting at specific degrees.