(Update) Unsure if this was either a bug in OSO mod or OSO Patch mod but Alduin would not pick up the Imperial Soldier on top of the Helgen Tower when the player gains control and before you enter the tower. I believe it was because 2 Stormcloak prisoners were headtracking Ulfric in phase 1 of the scene. Idk if that was the reason for Alduin not doing that while I tested the game. Anyways, I moved those 2 headtracks later on in the scene in phase 12. So this is fixed in V1.2.

So in the AlduinPerch Scene, I moved the Setstage 170 Trigger so its more on the left of the place so you could go and see Vilod and the Imperial Soldier talking to each other there since Vilod is injured there. In the vanilla game, if you were to approach them, the AlduinPerch Scene would end and the Imperial Soldier would get up and then try to attack Alduin from afar. I also added more Phases to extend the scene and also added a Timer before the Imperial Soldier talks to Vilod. I did this so the player could get there in time to trigger the dialogue. Idk if that was the best option though since if you stay in place and don't follow Hadvar to them, there lines would probably trigger from far away. Most of the scenes dialogue is also set to force subtitle so it shows them from far away when they appear. I also made the Torturer's Assistant level higher from lvl 1 to 3 and changed his health so its like 113 maybe. I only did this because he dies so easily on Adapt Difficulty. This change could maybe be a problem however as you may not be able to kill him on Master and Legendary? Hmm. I'm gonna give him the protected flag then. So I guess you may have to do the finishing blow on him then on the Stormcloak side. But eh. I couldn't fix him so he doesn't die so fast. So, the mods I posted on here has him flagged as protected. Also, for the carriage ride, I force subtitles on a couple of Elenwen's dialogue so you can see them earlier. And also on the 1st dialogue of Haming too.

So I have 2 of the OSO mod versions for this mod that changes OSO SE & the Patch mod. The 1st one is with 2 dialogues added. I added 1 of Lokir's unused dialogue for the carriage scene. It wasn't in the OSO SE mod & its Patch. I am not sure if I placed the voice/dialogue I found in the game's code tho in the correct spot for that Carriage scene. it may be correct but I just guessed. And then in Alduin attack scene when he 1st appears in Helgen, I readded the Stormcloak Prisoner02 person I think saying, "Dragon!" like in the vanilla/final game. It was taken out of the OSO SE mod I guess. I wonder if I could of instead using a new Dialogue Topic for it, I could of used the vanilla id or record header for that but idk if thats possible unfortunately in Creation Kit. So I just made a new one. And the 2nd version of the same mod in the old files is without those added 2 dialogues. It the one that is version 0.9. That one is esl flagged.

So for this mod, you will need to enable the (Intro Horse & Carriage Speed Slower Change.esp) above the other one in your load order I think. Well, for at least esl flagged, "Dialogue changes for OSO Intro (No added dialogue)" Folder one which is the 0.9 version. Its in my old files because I have it as a master for the file header. The one that adds 2 dialogues that has a (Sound) folder is not esl flagged and is esp flagged and is my main file I am working on atm. That one is version 1.0. I could not figure out how to esl flag it after I added the 2 dialogues into 2 scenes. Is this bad tbh since Opening Scene Overhaul Patch is esl flagged and mine is not atm? Not sure. The one that is esl flagged may need the Unofficial Skyrim Special Edition Patch or USSEP. But I think USSEP required for OSO Patch so you may need it regardless. You also need to get the (Opening Scene Overhaul modded intro thing) which readds the "Bethesda Game Studios, Presents" part in the beginning. I was browsing the posts/comments of OSO patch mod and someone put those back into it so I downloaded that for this mod I'm editing. The OSO patch one removed that I guess because Lokir and Ralof would talk to the player when its that black screen when it shows that title of ES5, Skyrim thing. Not sure if that's the reason it was removed in the OSO Patch mod tho but its just a guess. So this mod changes that back to the vanilla game for that part. So load order in the correct order should be,

Unofficial Skyrim Special Edition Patch
Opening Scene Overhaul SE
Opening Scene Overhaul Patch
Opening Scene Overhaul modded intro thing
Intro Horse & Carriage Speed Slower Change
Dialogue Change & other changes for OSO Intro

You could maybe put (Intro Horse & Carriage Speed Slower Change) above OSO Patch or OSO SE mods but I haven't tried that. I don't think it matters tho tbh. I did have (Intro Horse & Carriage Speed Slower Change) in a separate folder before but I decided to just put the esp into the (Dialogue Change & other changes for OSO Intro) folder just for this mod. Btw, I am not sure if this mod will work for the AE version of Skyrim or beyond 1.6. This mod is for 1.5.97 or the Special Edition version.

(Update) I fixed the problem so now you can flag the esp as esl in the 1.1 version. That version is flagged as esp tho currently. I am not sure if the OSO Patch mod that is a esp flagged as esl could work with this 1.1 one that is a esp and has no esl flag. But it could. I guess I could flag the esp as esl but idk if I would have a problem later down the line if I were to add new Dialogue Topics. So if you want, you could unflag the esl for OSO Patch so its only a esp again just for my mod. I unflagged the esl in the OSO Patch so its a esp only on my pc just incase. I think it could be fine either or but Idk. Also, if you use older versions of this mod, I am unsure if 1.0 would work on the same save file your playing on as 1.1. 0.9 may work but its a esp flagged as esl but does that change anything really if 1.1 is esp only? Got no idea.