The hand-written scanner claimed to put XML's entities back and did not, so a chassis with an ampersand in it matched no design and said nothing about why. quick-xml costs one small dependency, does no entity expansion and resolves no external entities, and left the wasm build 483 bytes smaller than the code it replaced. write_mul makes the reader testable: all 30 .mul files the install ships are read, written and read again unchanged, and the 35 units in them that this crate can score are worth the same on both sides of the trip. Change-Id: Id56b29605061ca7c8e020ab5c8cfb70d061a3505