"_[custom field id number]" suffix is causing issues
This custom field id number changes between environments requiring a lookup algorithm to get the correct field name when writing code.
Why add this ID at all? Developers should be entrusted to name their custom fields the way they see fit. If this causes a name collision that's on the developer. It's not the project's responsibility to manage custom field names.
At the most you should force a "custom_" prefix or something similar. Forcing an _[custom field id number] suffix causes more problems than it solves, at least for those of us that don't develop on our production server since these ids change from one environment to the next, depending on what order features get implemented by the organizational development team. PLEASE fix this. It makes custom fields nearly unusable for some organizations.