Hi,
Are the non-wrking entities missing from this list:
https://github.com/Sigil-Ebook/Sigil...MLEntities.cpp
These are the recognized entities that PreserveEntities can work with. This list is by no means complete. Please note that Qt BookView/Preview and even html5 aware parsers like gumbo literally remove all entities actually replacing them with the proper unicode character. Then upon return PreserveEntities simply looks up the unicode code values given back returned source code, and replaces them with the allowed entity codes in the list.
So perhaps, either the entities are not recognized by Qt widgets and or parsers as legal unicode characters and so are not properly converted to a specific single unicode value. If that is the case, PreserveEntities can do nothing to put them back in your code. I will take a closer look at the code to see if I can pass though all numeric entities (as opposed to named ones) and get them back.
Hope this explains things a bit better.
KevinH