A realistic goal is about 1 inch in length and 1/2 inch in girth. Tube didn’t say it but the data he came up with did.
Tube, a member early in this forum , did some regression analysis on the data members entered into the PE statistics area of this forum. Do an advanced search using the following. “Size’s PE data analysis”
This will help put it into some perspective. Larger gains are possible and reported, but are not the norm.
Take care and happy gains,