Is Mac OS Extended (Journaled) safe to be used as a developer instead of the Case-sensitive type?
Will this case-insensitive partition give me any problems in the future?


No. You should be fine.

In the default installation mode, the disk is formatted with case-insensitive filesystem (true for older OS releases before APFS). All the developer tools will continue to work fine without any issues. (I'd go ahead and state that the majority of folks run a Mac with this default case-insensitive format).

I have personally seen apps (Photoshop, Steam) not working with case-sensitive filesystem and hence have abstained from using it. (I once formatted the drive on my MacBook with case-sensitive filesystem, sharing similar concern as yours.)