If you plan to buy new lenses in future maybe it is worth to buy universal turret vf ? I used to mine so much that even when i am shooting with 50 mm i am using turret vf than this built-in one. It's much easier.
Once upon a time I made a very very rough measuring about what is the distance from which the parallax byass starts to appear for a 50mm lens and the Kiev viewfinder. I found that the distance was some 1,7m and onwards towards the camera. Let's add some margin for error and we get 2m.
This means that you cannot have parallax errors for subjects standing at 2m and farther. Otherwise my testing will have to be done again.
However, if your images show more or less my test was correct, then the most convenient tool is the Universal Turret Finder, providing you a good correction leverage for short distances. Even the UTF is not perfect here, but you will find it very easy to find the level of parallax compensation to adjust for a 50mm lens, or leave some free space above the head of your subjects, once you compose with the UTF.
In my particular case, like Bolas (and finally I am happy to find a pal on this issue) there is no Kiev without UTF, up to the point that two UTFs are permanently attached to my two working Kievs. And, like Bolas, I will still carry the UTF even if the only lens with me is going to be the standard.
Using permanently a UTF on your Kiev, changes a lot the character of your camera. You will be loosing speed of manipulation against the average Kiev user, using only the viewfinder. On the other hand the viewfinder with its great yellow patch will stop to be the compositional tool on behalf of the UTF, and will remain as a focusing only device. You will be spending more time peering through a high quality glass with almost zero loss of light. In other words, you will take the best of the Kiev viewfinder without paying the parallax tax.
But, of course, the UTF represents some investment, and perhaps you may like to spend some more time with your camera before that.
Cheers,
Ruben