OP, I understand your frustration. I didn't get the luxury of watching cutscenes when I did Castrum and Praetorium on my main (the character you see me posting as), and watching the again in the inn room wasn't the same. Before the circle even drops to commence the duty, people already start complaining about the person(s) they see that are "Viewing Cutscene." This even happened on an alt when I was watching the cutscene before you fight Ifrit for the first time. I got in the habit of just skipping dungeon cutscenes because I was tired of getting yelled at for it, but I regret doing so. However, changing those two duties to solo instances would take a lot of reworking and tweaking, and I don't think that's something the devs are going to be willing to do. Plus, as mentioned by someone else, it does mess with the lore aspect, and the devs (barring that Yokai event) are very peculiar about lore, and make a lot of restrictions based on it.
I would highly suggest asking friends to run it with you, or make a PF for it. Don't just pick the "story" reasons objective either, type out that you want to watch all cutscenes so people who see it know, and also let them know when they join (because I don't think many bother to read the PF objectives, and just join when they see the duty--like the Ex primal clears people join and then complain when they learn its a clear and not a farm). I plan to ask my FC mates to run it with me on my alt so I can experience it on her as it should be experienced. Still doesn't take away the regrets I feel for my main though.
If you decide to run it as is, and people grief you for it, report them. And hopefully something will be done about them. A lot of the GMs in this game are very understanding and helpful, and I think they WILL take actions against player who threaten to kick you for just trying to do the story as it was designed to be done.