The only carby part of this recipe is the Mayo! But it holds the kugel together, and adds great flavoring so it is important. I wouldnt worry about squash.
The reason I wrote optional by chicken soup mix is because the standard Osem has MSG which some pple are very particular about. I heard that Leiber’s has no MSG, check the pkg. I personally, think it adds loads of taste to anything so i dont hesitate with a little A Kugel like this does need plenty of spicing.
If u r only putting in an egg white, u will probably need 2, though I never tried it.
Sometimes I even put the mixture into muffin tins so it looks a little nicer on the plate.