Looking at Client start exception after today update - steam [SOLVED] - #33 by Trii_Seo, it looks like the native launcher does some funky stuff and moving only the launchdarkly library may not be enough. You’re probably going to need to move all of the dlls it searched for and failed to find, not just launchdarkly.
Alternatively, ditch the native launcher and switch to wine-staging with the native windows installer. I’m not sure how much longer the native launcher is going to work with upcoming changes to the oauth API