My experience has only been with the FZ150 & FZ200. In both cases, we do not apply any force on the lens whatever it is we wish to add on. In my case, I have used 1.7X & 2.2X as well as macro conversion lenses. For these 2 camera models, Panasonic (and OEM) have an aluminium tube adapter that screws onto the camera body around the original lens. The conversion lens then screws onto this adapter without touching the original lens, hence applying no pressure to it.
This is always recommended because weighing down the lens will affect the internal focus/zoom motor which might shorten the lifespan.
The problem here is (IIRC), the FZ1000 body does not come with threads on which you can fix any tube adapter, so you will have to take your own risk attaching the lens directly to the scope. Good luck !