wilbur
I don't get this fear of oversharpening. I agree with Brian when he said above that waiting for your plane to stop taking a clean shaving before sharpening is bad practice. That's why I suggested taking some time to refresh your edge before using your plane, whether you think you need to or not.

If the worry is that it's not an efficient use of your time, maybe this will help. As you know, I don't really use Stanley planes on a regular basis. I do have a #4. It's been ages since I used it last. I took my plane, took out the blade, disassembled it from the chipbreaker, refreshed the edge on my highest grit waterstone (about 20 strokes each on the bevel and back), wiped it clean, and put the plane back together. Total time: 2 minutes, 2 seconds.

The edge felt sharper to me compared to before I started. The edge was good enough that I could finish plane a piece of quarter sawn red oak without tearout.

I wasn't trying to rush the process to get this time. I also don't think I was able to do this in 2 minutes because I'm particularly talented with Stanley planes. If I used western planes on a regular basis, I'm sure I could improve this time. I'm sure anyone here that uses Stanley planes more than I do could do this more quickly than I did.

The time it took me to refresh an edge on a plane blade is trivial. For me, with Japanese planes, once I do this at the beginning of a shop session, the blade is good for the day. If the argument is that I wasted two minutes unnecessarily sharpening my blade, I can only say that I wish I was so efficient in my shop that saving two minutes had a meaningful impact on my productivity.

If you find that it takes you longer than I did to do this task, I can assure you that with some practice, you can do this too. That should give you another reason to adopt this sort of practice.

If you're really opposed to doing this each time you plan on using your plane, then try every other time instead. Or every third time. Just as long as you're not waiting for your blade to get dull to the point that your plane stops taking a shaving before sharpening it.