Not a bad idea. In my view the instant return mirror is the most over-rated of all camera gizzmos. My old Exakta VX iia had no instant return mirror, and once I was used to the idea I didn't see that as any great disadvantage. Kiev 60 also has no instant return mirror.
You know, sometimes a simpler technology is better in terms of less bugs to attempt to iron out. Like you, I agree with this statement.
Back in 1966 when I was 16, I got my first 'real' camera, a Minolta Autocord CDS, primarily because I was
told that composing on such a screen would be easier and better. When I got my first 35mm SLR, a Canon AE-1, in 1978, I learned rapidly that this was not the case.
We are told over and over again, that lack of an instant return mirror hampers our ability to make great pictures because what we do not see afterward, becomes a perilous omission. It does not. There are many truisms in photography that are primarily marketing ploys with little or no sense. - David Lyga