However my system appears to be working ok.
Hi, Upgrade from LE9 to LE10/11 is not recommended because too many things is changed and that often lead to different problems. But that not means always ends with problems. I suggest to you, test your system and if you don't found any issue, keep it as is now.
The "clean install" advice is all about mitigating add-on update problems that can occur with the Python2 > Python3 change from LE10 and later. If users have a simple setup there's generally no problem with the direct update. However if users have third-party, or not installed from a repo that contains the updated Python3 version of the add-on things can crash, and if that happens it can be challenging for less technical users to self-recover and we're not staffed for the effort. If your update went fine.. "if it works, don't fix it" applies 
