The procedure or the 11 is not the same as the 15.
"Supposedly at the end of the procedure it asks to clear the files (saw it on YT video) and this bit worries me." It will clear only what is necessary; for G10 it is very little.
Btw, in IPL mode, enter "99", press ENTER, it will ask for # of axes, enter that, then the OPTIONS. Then answer Y (ok to CLEAR).
You can lose your data anytime, so always be prepared to restore the data by having complete backups.