Many thanks to Alexander Hagberg for sharing his knowledge!
Here is what Alexander has to say about the new Nosram 4200 Hyper LCG 2S Pack:

 

„Tech tip! The Nosram 4200 Hyper LCG 2S pack (#999753) is a bit longer than other shorty packs on the market (it utilizes the full shorty size!) which leads to exceptional capacity. However, to fit it to your XRAY X4 or T4 chassis using the optional shorty brass weights (309861), you will need to cut one of the weights shorter by 0.5mm to make it fit (with a bit of play for free movement). The battery must be able to move back and forth slightly. See my X4 video about the battery mounting system for more detail!

This tech tip applies to the LRP GmbH #432273 pack as well!“