Hey Dan, great to have you back
Some people tend to tolerate fat in the backload better than others. In general, if you’ve got the macro space to spare, fat in the backload is fine. It also depends on how many carbs are in the backload itself. CarbNite is another story. It’s a good idea to keep long chain saturated fats away from high insulin levels, so keep it to MU fats and MCTs.
The type of carb does not necessarily matter as long as you’ve gotten a large insulin spike from something like a pro shake with CarbShock. In fact, a lot of the more common choices people make are more medium-GL than high anyway, like sweet potatoes, rice, etc. As long as you’re getting a big spike to shut down catabolism and keeping the overall carb feeding window short, you’re doing what you need to do.