I have had to unsew some of my hand-pieced blocks. They are almost as hard to take apart as some of my machine sewn ones.
There is a "however"
The stitches need to be small/short - less than 1/8 inch showing (I do not know how to count hand-sewn stitches) and back stitched every 4 to 6 stitches. Anyway,that's what I do. Ginny Beyer's hand quilting book is awesome!
Basting type stitches will not hold together . I picked up some squares that had been "sewn" together. Those did not even survive being picked up.
A fairly short, interesting article on needles:
https://www.ngv.vic.gov.au/the-sewin...9th-centuries/