The quality of the modules inserted to the emitter resets when switching the quantum mode.

Possible bug in the 'local function save_modules(entity)':
AFAIK, the follow string
'table.insert(modules, {name = stack.name, count = stack.count})'
must be
'table.insert(modules, {name = stack.name, count = stack.count, quality = stack.quality})'

Good catch! Thanks for the code snippet. I'll include this fix in the update planned for later this week. Thanks!

The quality of the modules inserted to the emitter resets when switching the quantum mode.

Possible bug in the 'local function save_modules(entity)':
AFAIK, the follow string
'table.insert(modules, {name = stack.name, count = stack.count})'
must be
'table.insert(modules, {name = stack.name, count = stack.count, quality = stack.quality})'

Update is live! I've added the quality parameter to the save_modules function as you suggested.