Looking at the bytes

The Section Explorer plugin, installed from Plugins ▸ Browse Plugins…, is a hex editor over the scenario: every section with what the editor knows about it, its bytes coloured by field, each value shown with its meaning, and sections added, removed, renamed or reordered. An edit there is applied by rewriting the file and reading it back, so a raw change to any section, modelled or not, reaches the whole editor, at the cost of the undo history.

Plugins reach the same thing through api.document.sections in the plugin API: the file as Save would write it, every occurrence with its offset, and the same replace, rename, insert, remove and move operations.