Increase in Compilation Time -> why?

A long compilation time could be caused by multiple factors - there is no easy answer. Name a few: a larger design used, a different devices, changes in project settings, design coding style, a large address/data width RAM or possible a bug in the tool.

Example KDB:

https://www.intel.com/content/www/us/en/support/programmable/articles/000080504.html

You may checkout this user guide on how to reducing compilation time:

https://www.intel.com/content/www/us/en/docs/programmable/683236/22-3/reducing-compilation-time.html

I hope my reply helps in answering your questions.

Best Regards,

Richard Tan

p/s: If any answer from the community or Intel Support are helpful, please feel free to give best answer or rate 9/10 survey.