Why not just take a bit of an IQ drop and get some close up filters? Ive yet to try it but people keep saying that CA can be post processed out, which I might look into at some point I guess.
Thing with macro photography is to me it would be like a fad, great for a bit.. then i just wouldnt bother
Each to their own, I love being able to capture what is pretty much invisible to us as an image. Telephoto lenses for birding to me would be a bit of a gimmick I find, and as for using them for getting closer to insects, I find part of the fun is chasing them around a field