I’m not into “regular” arch viz, so keep that in mind. You don’t mention if lighting is expected to be accurate or beautiful.
I used to use 441/29 for sun&sky, but recent discussions have left me with 1000/200 - as a starter which is then adjusted for time and atmospheric conditions. Using Photographer addon, -6.64 in color management exposure corresponds to sunny/16 rule - nothing reasonable albedo wise in front direct sunlight will be over exposed. I use Sun Position (built in) addon to set the position in the world, and use the time of the photo, also get the northing of the building/room. It’s also important to get photos from the outside to see if anything blocks or reflects sun & sky which might affect the final outcome. Even if I can’t see it, I also add a ground plane with about the correct materials and elevation relative my my floor. I would also get shots with and without interior lights, with and without outside lights blocked out - just because it’s critical for what I did - make sure to shoot with same manual exposure - keep the exif’s handy. Photographer addon should give you means to set exposure similar to the reference shots. Make sure window glass is not casting shadows. Using correct materials, for now render with reflection caustics on to get light transport from this.
Adjust the lighting until it matches the reference shots. Even if it has noise and may be unusable, you have a reference you’re trying to match. Now you can start tweaking and faking it, such as replacing indirect light from curtains with area lights, use tricks to make up for lost transport if rendering without caustics, faking indirect lights and so on.
The tl;dr is: I don’t use HDR, but sun/sky 1000/200 @-6.64 for sunny/16 initially with realistic ground, outdoor, and materials. Photographer and sun position addon for exposure matching and positional matching. Adjust exposure and adjust until satisfied. After a reference looks good enough can you start tweaking for hacks and performance. But my goal wasn’t beauty, but indication of light conditions and what needed to be done to the space to meet our criteria (outdoor lighting was my enemy which I guess was lucky because it adds the most noise).