To me it sounds as if you have a relatively large project, with 10 CPUs, there are lots of analog i/o, and on some CPUs there are 2-3 programmers working simultanously.
Working several people on the same project is always an added complexity.
The way you describe it, it is clear that you are developing the program "concurrently", i.e. you a doing it on a running system. Now that adds yet more complexity.
I can imagine that you are running into cost overruns if all of this is because you are behind schedule. You must be behind schedule, because you will only the problem with initialising datablocks when you change declarations. And you mostly change declarations when you are at the beginning of coding.
It is easy to give good advice in hindsight, but I always simulate the hell out of my projects so that the program is 90-95% finished when I get to the commisioning stage.
Developing concurrently is a nightmare challenge.
If I were in your shoes I would get the multiuser option to TIA. It costs 600 € per license. That is absolutely nothing relative to a big project, and if it can cut just 10% of your time, then it will have paid off already.