It will work fine because WD Red is physically the same as WD Green, apart from an additional motion sensor. The TLER-firmware is not needed for single-disk setups, but it will work the same as any non-TLER disk would - up until the point a bad sector was detected.
For Windows desktops using harddrives as single disks, the data is given no protection at all against bitrot. This means that the recovery functionality of the harddrive is the last line of defence to get your data back in case of an unreadable sector. TLER basically kills this last line of defence, so generally using WD Red as standalone drive is not really recommended, unless of course you keep good backups. One argument against this is that you need backups for your WD Green too, but reality is many people use harddrives with data that is not fully or recently backed up, if at all. So using a TLER disk for this purpose would decrease the chance of successful data recovery should a bad sector pop up. It would be worse if this happens on filesystem metadata, because this can cause entire directory nodes to become invisible/inaccessible or the volume simply not be accessible at all. Advanced recovery tools may bring back files in bits and pieces, but this is a very poor situation to be in.
So my recommendation would be to focus on good backups as usual, and only use WD Red or other TLER drive when you actually need TLER. If you have one lying around you wish you to use as standalone drive, that is perfectly alright though. But keep in mind it has less chance to recover unreadable sectors so keep good backups.