Haven't watch the HU yet, but plan to do that and will keep this in mind. Or if you are interested about my short thoughts i can break that down shortly here in the comment section, but then please tell me exactly when was that hand.

I have some FR and other stuffs planned at the moment, so not sure if i will make a video about HU, since didnt get too many request. But will see...

Great questions btw...And tough to answer... :)
About this current stud hand it's kind of close. A lot of depends on the nuances. Like the ante size. For example if the game is played with a big ante, let's say 150-300$ CG, 50$ ante, and the Ace is opening 100%, then even AK-9rb is an easy 2bet. But if the game is played with a lower ante, like 150-300$/25$ ante, and the player with the ace opens "tight" (thats still probably a lot of hand, somewhere between 60-80% i guess), then even AK-9hh can become a fold...

"Same" for stud8. Every hand is unique because of the dead cards, ante size, opponent frequency....And also in s8 because the game is split pot some hands can played either way. For example let's say a 3 open MP, we have 46-5, and there is an 8 and a 2 behind us. This can be played a 2bet easily or also as a flat call. If the antes are really high than it might be better to 2bet and try to get it HU. But in this spot usually I think we should also think about how our opponents play. If the opener is a very weak/bad player, plays incorrectly post, and the 2 other player behind us are really good than I would 2bet for sure, even hands that definately wants to flat (let's say 23-5rb). But if the opener is a really good player, but the players behind us are bad, then i would call even with some very strong hands (like this 46-5, or maybe even 46-5hhh) to let them in and play hands that they should fold even for one bet (for example the 7 should fold a hand like 38-7rb if we flat, but some weak players call with these). 456hhh, and also 456rb here can be both played either way, because they play great HU and multiway as well. However there are some hands which are just a 2bet all day, because they play better HU (like JJ-5rb... or 85-5)...

Hope that answer your question, but you might give me a good topic to make a video about (when to 2bet in stud8 and when to flat... :) Might consider that, so if you have any specific hand/question regarding this topic feel free to ask it/post it :)