Not quite sure why the recipe called for a 90 minute mash. the ingredients listed are typical of an IPA, I use them in mine and my mash is for 60 minutes and they turn out wonderful with no issues.
I have followed recipes that call for 90 minute mashes and have only done them with 60 and they have all turned out great. Are you sure it was not a 90 minute boil?
I really think it will be fine