Starting maps like this is hard. I remember many years earlier when Google maps was new and disastrous, sending massive truck detours through small sleepy villages and encouraging inattentive driver to drive into duck ponds. Then when Apple released their maps Google already had 7 years of improving theirs, and they had made good use of that time.
It was a mistake not allocating more resources (/spending) to improving it sooner after the release turned out so badly. They always move slowly with their projects. Even now their new map updates are spectacular but the mapping vehicle fleet seems too small and is taking a long time.
Not sure the lack of fan matters, as an app dev you probably wont be hitting hard both cpu and gpu simultaneously for long durations. You’ll just be bursting the CPU for app compiles and simulator startup, that’s not too bad.
I’d be more concerned about RAM. 16GB is probably a better idea than 8, especially if you have both web browser, IDE and simulator running. Look for a refurb or used anything with 16GB of RAM.