Redwood

Hello! I've made BigWorld setup for myself long time ago based on 2.3.67.3 build of BG2EE. Lots of changes were made manually through override and dlg (translation fixes, item fixes, creature fixes, etc). Some time ago while my legacy of bhaal + scs run i've checked for random crashes to desktop w/o any dump during long tough fights (5-10mins and longer ones). After some researching i found that in 2.5 update there was many tweaks for engine stability and i've simply tried to change my  2.3.67.3 baldurs.exe to 2.5.16.6 one w/o updating other data resourses from last patch ('cause they will 100% break my current setup). Crashes while fights dissapeared magically.. I've tried to replay some saves before problem difficult fights - all is ok, no ctd.
 
Now i'm in some kind of paranoia that some ingame formulas can work in the wrong way (like battle throws, saving throws, AC/THAC0 etc) 'cause data resourses from 2.5 build were not inplemented ..
 
Am i right and this kind of fears are real ones?)