Since no one else has replied, I'll throw in my 2 cents.

Possible?  Absolutely.  For reasonable cost/effort?  Doubtful.  There are small lathes with this feature built in now days, but I'm not sure what the mechanism looks like.   Probably the easiest solution would be to retrofit the newer style carriage to your current lathe, but the cost would probably be excessive.

You could rig up a stepper to the gross feed, but tying it in to sync with the leadscrew might be problematic.

I'm open to suggestions and interested in any solutions you come up with on your own.