No rom should ever mess with the IMEI. Also with the proper backups you should not have to worry about it.
You can share ways to trouble shoot it happening but no, no tools or how to will be allowed.
Sir, this "should" is a very interesting word. Yes, no ROM should.. but there are ROMS and I am a victim of such a problem. Forget everything else when
I myself am victim of XOLO Q800 Stock ROM which fails to recognise my IMEIs every single time as that needs to be pushed by SP Flash Tool.
The more interesting part is - so far as I have tried my luck - Backup in CWM also fails every-single-time whenever I tried to recover. However, this has helped me build a practice of backing up my ROM every Sunday (but for what?).
Now please tell me how can a noob user like me benefit from such a great resource like XDA in a case like this? For everything else, Yes, I do love XDA since 2008 ever since I joined as it is indeed an unparalleled resource.
I wish 'admin' gets my point, if not what I said in words. Please accept my sincere thanks for that in advance.