Since each of these interpolations is only 2 or 3 addresses long, it might be less confusing for humans to represent them with commas, e.g. 78,82,86 or 58,62.

Or at worst, 2 or 3 "even" interpolation lines, using one per building level I'm guessing. Right now they're a little inscrutible when looking at the map even if they're correct!

I'd like to tag the entrances to each building or staircase too, while I'm at it. That tends to work well with flats.

Tagging more simply and typically might be more useful for data consumers too. Even OSM Inspector (!) gets confused by the addr:interpolation=4 notation. The wiki calls it an "unusual case", and I can see why, but it does document it.