I'm a voip tech with 10 years of experience working on the level-2/NOC department for a US company, I'm familiar with many different SIP devices, softphones, AtA, ip-phone and PBX systems, I'm able to analyse, troubleshoot, configure and customize any sip based voip system. I read your project description, and I can certainly help you with your 3CX system on a emergency basis. Feel free to contact me at any time to discuss more on this project.
Thank you.