update: I modificated the Things and it works very well for me, no wobbling anymore !.
i also got the tronxy X5 and i also had the issue with the wobbling printplate. Sry guys but all the proposals here are to much efford and so i decided to build my own version. First i Planned a second z motor but now i tryed only one side support and i am testing it right now and so far it looks also good with one support. I will report if it is not enough. You only need an additional rod and the rod fixation also possible to find on thingiverse under tronxy x5. And you need a bearing.
I Hope someone can also use this quick and simple solution to stabilisize his x5.