Parts are saved when project is saved, depending on what you are doing saving parts separately has some uses, for example if you tweak some parameters but did not want to keep them, then reloading the part (that you previously saved) will restore your part without undoing any other changes you since made to the project. I see saving parts as a way of allowing the autosave to take care of other project settings, whilst allowing parts to be saved separately if needed.
So in summary, if you are happy with how your project sounds save the parts, then you are free to tweak away, safe in the knowledge if you want to revert to the saved parts you can.
That’s an error : in that case, if you reload the project, saved parts are not reloaded!
So you should save parts first.
Anyway parts settings are stored with banks when you save the project. No need to save them. It is usefull only if you mess with parameters and want to reload settings in live conditions, but a project reload suffice.
It’s another store level I don’t use, but some people may prefer to do it. It’s not a bad thing, but it requires more time. Maybe depends on how you use OT.
Other caveat : you can accidentally reload a part and loose new settings.
You can also save banks, hence save all its parts, patterns.
Also adding that parts allow you to change sample slots. So part 1 could be samples 1-8, then part 2 can be 9-16 etc. Great for techno cause you can have 4 sample sets in one bank giving you essentially 4 patterns per “song” with 4 of those songs in 1 bank.
In the project menu. Theoretically faster.
Not sure how it can be usefull. Maybe if you have a corrupted bank in a project?
I recommend it for really paranoid people :
Save sample settings, parts, banks, project, and use SAVE AS NEW to be really sure.
Then use PURGE/COLLECT SAMPLES and upload the project to a cloud, copy it to several memory stuff. 10 CF cards should suffice.
Tons of explanations and exemples in the manual :
SAVE CURRENT BANK works like the save project command, but on a per bank basis. The command will save the settings and assignments of the currently active bank. RELOAD CURRENT BANK works like the reload project command, but on a per bank basis. The command will revert the currently active bank to the previously saved state
Per track, in a bank, 4 sample slots with parts vs 128 with sample locks…
For me it’s really problematic to change part in a song just for samples assignments : if you change parameters common to all parts, you have to set these parameters again on all parts, and save them again if you always save parts. Time consuming in the end.