Quite vehement.
Nothing is written in stone, yet, with Ma3 itself on hold. Combined with the fact that Jung & Gary are good friends, I don't see why Gary has to be ostracized from the SDB strip. In fact, I feel it is wasted potential using him as a throw-away gag/sighting. It is titled Sticky Dilly Buns after all, not The Ruby Chronicles. Even more than Ma3, SDB should be centered about Dillon... or at least should be if the title is to be believed. Granted, Ruby and Angel and their dramas have been center stage for quite a long time. Is that making Dillon just the main thread that tied SDB back to its parent strip Ma3? Maybe.
Would it interfere with Andy & Ruby's relationship to introduce Gary as a friend-of-a-friend to Ruby? Maybe, and maybe for the better. Gary helps people see to the truth of their problem. See Tracy and Zii most recently. And as I mentioned before, Gary talking with Ruby could be seen as a sort of litmus test to the depths of feelings he has for Ruby. It might make Gary once again the doormat for the script, but why not once more before the strips conclude?
As far as being used as a human vibrator, I agree that using him as such wouldn't work narratively. But let's look at Gary. Setting aside the Limbo-like status of Ma3 right now, he is stuck in a FWB relationship with Peggy that doesn't show signs of improving. Didi & Zii are still together, and with Gary being honorable he isn't going to try to break apart their relationship. He has no other prospects on the horizon. So if it helps move the plot along for Ruby, then why not introduce Gary to Ruby properly and respectfully? No hanky panky required, just simple coffee talk.
Some would argue that Ruby would feel that she was being unfaithful to Dillon. Dillon seems to have gotten over his crush of Gary. I am sure he may have wondered how things would have been with them as a couple, but it wasn't meant to be. If Dillon can get over Amber using Gary, adult minds should be able to take Gary as fair game. Some could also argue that since Gary has been with Amber (even if not exactly full-on sexually), that there is good enough cause for Ruby to nix him on the spot. Once again I would point out that adult minds should be able to realize that Gary himself - while duped for part of it - was happy for the opportunity. Gary is mostly innocent, and should only be getting a bad rap from Ruby because of comedy scripting & because of his Amber-Amber lusts before becoming more mature. In fact, he's actually a reasonably damned good prospect now... if his partner can deal with his nerdisms. Both Amber & Dillon can attest to his sweetness and caring virtue. And Gary isn't a hand-me-down or discard from either of Dillon or Amber; he actually had serious potential for both of them should the stars have aligned differently. Adult minds clearing away the preconceptions and misplaced emotions would see that Gary isn't the worst.
If the creative team doesn't want to do so, fine by me too. But if they are going to put chocolate into the peanut butter, might as well enjoy the combined snack and not complain about it (Reese's peanut butter cup reference for those who don't remember or are unaware of their ad campaign ages ago.)
[/takes off FIRRIB cultist uniform]