No it is standard way to add some other storage’s. Only it will not add to your root home folder, but as additional folder.
if you add it as Local storage, there will be no speed degradation at all.
Just be aware that if you modify/add/delte files not via NC but locally, you need to perform rescan of this external storage. You can use this command:
Or even add it to crontab Automate OCC Filescan - #22 by gas85
If you will have more storage’s, them use this nice script: