I have looked the documentation but seems there’s not a way to achieve the current settings about pitch / slice mode (amiga/ft2 or renoise).
Can you confirm that? Do you think you’ll expose these settings in the future ?
The majority of import compatibility options are just for getting basic stuff imported and have the lowest maintenance priority (low to none).
So for that reason, i doubt there will be API functions coming for those unless the devs are bored enough to do it.
But if it is a must, you can use the file API calls to retrieve these settings from the song file, be it that you need to write a wrapper to unzip the file (I thought the tool updater used one) and then ofcourse a routine to read the XML data from the song.xml. The only risk you have is that if the user decided to change it while in session, the changes are not directly saved to the songfile the user chooses to.