How did he know to go up in weight? Would he have made similar gains if he stayed lighter?
He would have made great progress.
He didn't know to go up in weight, he wanted to. I believe Ltl chose to eat more aggressively because of personal choice. I do not wish to speak for him, but I am certain his decision was a conscious choice based on some of the reading he did about Blakely.
Max is 170ish I think, why not eat his way up to 181 or 198? Would he be even stronger? JB is ridiculous strong at 300, but Honeycutt stays at 198 and is just as ridiculous strong respectively, but why didn't he go up to heavyweight too?
Max hates fat and lardocity. Simple. Max has no interest in gaining weight. Again, I do not wish to speak for him, but have been his friend long enough to know that he made a conscious decision not to gain weight because he does not want to get fat.
All of these choices are individual. The reasons are all personal. This is a decision you need to make yourself. Larger lifters lift more. Some people want to lift as much as they can, bodyweight be damned. Some people want to lift as much as they can and keep their weight more regulated and on the healthier side.
Let's face it, there aren't many 60 year old men that weigh 300.
The answer is personal choice. You can have it either way in this sport. You need to stand in front of the mirror and ask yourself who you are, and if the weight gain risk is worth the reward. That is the question you are seeking.
I do not personally want anyone to gain a lot of weight before they get there numbers up. Use the weight gain, if you decide to go that route, when progress becomes a struggle.