Is the Mission Night Op55N1 the end of the game?

[Theuzim]

Speak leaders. I've been playing the game a lot on another platform and I stopped at one part a while ago because of a question. I believe I'm one step away from finishing the game's main story, but after that. From the patch that came with the expansion, I'm receiving a lot of calls with a lot of missions, and I really want to finish each one of them. My question is: If I play the Nocturne Op55N1 mission and finish it, will I be able to go back and do the other pending missions? What kind of influence will these side missions have if I do them after this one ends (if I really can)?
I say this because Silverhand is always with me and always says something fun or interesting during the mission. But anyway, these are my doubts.
I sincerely ask that anyone who will eventually se this post, answer me with no spoilers, please.

[Theuzim]

Missão Nocturne Op55N1 é o fim do jogo?

Fala lideranças. Estou jogando o jogo bastante em outra plataforma e parei em uma parte a tempos por conta de uma dúvida. Creio que estou a um passo de finalizar a história principal do jogo, mas após a att. do patch que veio junto com a expansão estou recebendo muitas ligações com várias missões, e to com mta vontade de fazer cada uma delas. Minha dúvida é a seguinte: Seu jogar a missão Nocturne Op55N1 e finalizá-la, eu vou conseguir voltar e fazer as outras missões pendentes? Que tipo de influência essas missões secundárias terão se eu fizer elas após o fim desta (se realmente tiver como)?
Falo isso pois o Silverhand sempre está comigo e sempre diz algo na missão e pá. Mas enfim, estas são minhas dúvidas.
Peço encarecidamente que quem me ajudar não dê spoilers por favor.
Desde já, grato a comunidade.

[Bogmore]

A search would have told you that you are "reset" back to before this mission after finishing it and there are quite a few ways to finish it, some depend on your previous choices.

[Silverbane7]

The game will warn you about 'point of no return' when you reach them.
Specifically (in your case) outside of the place (Embers club) where you go to start this quest.

When you choose to go there, do so slowly. Walk towards the place.
Let the game save its 'point of no return' save.
Because there is a known issue with moving too quickly towards that elevator, that can affect saves.

After you have finished the game (by whichever choices you chose, from ending the quest you are talking about) the game offers you 'just one more gig' as an option.
As Bogmore said, this drops you back at the 'point of no return' save, with any bonus items your chosen ending gave you for finishing.

But, sometimes the 'point of no return' save gets a bit borked. V is moving too fast, the game starts to save outside the elevator, but finishes the save INSIDE the elevator.
(Honestly, that lift has a higher kill count on players saves that Adam Smasher has on victims XD)
It makes the save act as if you are still inside that area, putting V in to a peace state.
No jumping, running, quickhacking, cannot draw weapons, throw grenade anything.
(Which is why I say it has a high kill count for saves. Many players have had to go back to previous manual made saves because of it)

So, don't make a quick save before going close to that spot. Make a manual save (suggest you make it facing the tarrot card image, so you know where you are and what you are doing there, saving. So the card acts as the visual thumbnail to remind you)

Then, hit G (or gently tilt the control stick, if using a controller) and just...walk there.
Should help you avoid the special save messing up.

(Since, you can only continue on to redo other ending choices from a borked save, even if you wanted to go back, do more side content, from it. V can't fight or defend themselves in peace mode. So you can't do much of anything if its stuck like that. Why I suggest the manual save before that point)