Tapered Edge Which Side ?

[DiyedAgain]

Hi! All,

Just catching up on some DIY jobs and got few questions if someone could point me in the right direction.

I've put a door into a poorly done archway, me dads a shop fitter and cursed the person who did it nothing was straight.

Now the whole wall is concrete as my house is a prefab and when they did the arch they took to much out of the wall to take arch out and rebuilt from scratch without it being a very expensive job with an rsj so we built it inside the supported arch which had just enough room for the doorframe and door.

I got some cuts of sound proof boards from a wall we built with a tapered edge which I am going to use.

So me question is would I put the tapered edge to the joining side to the concrete wall, the issue I got is that I can only take the tapered edge on the upright edge as the curve of the arch will take the part flat part as I cut round (I have templated it).

Or would I put the tapered edge to the door frame which will cover it with architrave.

I've done some photo to show what I got. Any advice would be muchly appreciated.

 

[Smudger1]

Square edge flush flat with wall. Taper to architreve side, scrim joint prep and skim all wall.

 

[Monkey Boy]

Don’t matter on that job better off cutting off taper edge getting rid

 

[Retired Spread]

overthinking that sunshine just get the fkers up