I had emailed Trijicon about the Huron and Ascent back in April asking about this very thing. Here is the reply I received:
Thank you for your interest in Trijicon® products and for your inquiry. I forwarded your concern on to our Product Manager for review. He informed me that the recommended 2.2”-3.2” range is where everything is optically optimized. In actuality, the eye relief is greater than 3.2” with a clear sight picture. Unfortunately, theoretical or functional eye relief data is not yet available.
The Product Manager additionally informed me, however, that he has personally used these scopes on rifles chambered in 375 H&H and 45-70 Govt., with no issues and plenty of eye relief. We have also sent samples out to a group on a dangerous game hunt, who were all shooting 375s and 416s. There was no person in that group that experienced, or mentioned any concern about actual eye relief.
Hopefully this will help alleviate your concerns.