Hi Dan,
First, I don’t think those fasting BG are "dangerously close to a limit"…because you are eating low carb, and that is what your body does to compensate…called adaptive glucose sparing. My waking BG went up when I started LC in 2011 and remains around 100. I re-listened to an interview with Dr Naiman this morning where he explained it well….start at Minute 40 here: https://www.youtube.com/watch?v=XhhoJAY96FA.

But if you do want to improve it, you can add healthy carbs. More vegetables, root vegetables, tubers, fruit, dairy, etc. Carbs that are Nutrient dense. We need some fat for hormones, but carbs and fat are interchangeable sources of energy. Marty's focus is on getting all the nutrients you need for satiety.

With your unique needs, consider taking the Macro class to find exactly what works for you, or join the Optimising Nutrition Community to ask questions and have access to 1700 nutrient dense recipes and meals. There is a specific article for weight gain after cancer treatment: with photos of nutrient dense meals. https://optimisingnutrition.com/nut...s-meals-cancer/
Also there is more info on Bulking for athletes, but I’ve not used it. It is listed as Moderate Carb and Moderate Fat.