Managing large taxonomy
Firstly it depends on your local environment. 700 Taxonomy terms are not a lot but calculation might be affected if your local environment is not powerfull enough. To mitigate your performance drawbacks take two steps.


Make sure you are using php 7 because it actually has a significant performance increase.
Increase your php memory limit to 128MB. Find the memory_limit variable in php.ini file and add 128MB next to it.


Now in the case of your calculation of depth after re-enabling the module issue I guess the correct path to take is the issue queue of the module itself. Issue Queue