How to tween only certain parts in a welded model using qPerfectionWeld

I need to tween things such as a lift, for an air carrier ship, the ship is held together with qPerfectionWeld since there is a lot of parts and I cannot do it manually.

I have been looking everywhere for answers but to no prevail. I have been trying to do what some people suggested, which is to use relative tweeting but this does not work due to the way qPerfectionWeld creates their welds, I am unable to accurately make a tween.

Ex: My lift has 3 destinations, (Top) Flight Deck, (Middle) Sub Level 1, (Bottom) Sub Level 2. I am able to script the CFrame goal to go to the CFrame of the stopping block for that level, but since the welding script welds a part in the very back to the lift and the CFrame is relative to the back part I cannot simply do {Value = Sub2.CFrame} and play it.

Any Ideas, Suggestions, or Tricks?
Thanks,
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