Morning Cletus ...... IMHO I'M thinking I would want the originals stored in my LR Classic. Thats where all your really serious business is done. So I would be checking that "store originals locally" even traveling. At least until we are certain of all the Whys and Where fors of the CC Cloud. In LR Classic I checked the box that allows me to specify the location ( new folder) of images from LR CC Mobile.
I'm not sure you're fully understanding these various options, so let me try to clarify.
The "Store Originals Locally" option is available only in the new LRCC desktop app, and those stored originals are only accessible by that LRCC app, and not accessible to LR Classic. What are available to Classic are any images "in the cloud", provided the Classic catalog is sync enabled, but those images are downloaded not into the LRCC workspace, but rather into Classic's own workspace (i.e. the existing Classic folder structure) via that Classic>Preferences>Lightroom CC tab.
So in a combined Classic and LRCC workflow situation, which Cletus is talking about, it probably makes zero sense to have that "Store Originals Locally" option enabled in LRCC when it's running
on the same computer as the synced LR Classic, unless the plan is to take the computer on travels and leaving the Classic photo library back home. But even then, it's a binary on or off checkbox, if it's on a copy of all the synced files would be downloaded into the LRCC workspace, which probably isn't a great idea either. Perhaps better to leave it unchecked and work with the smart previews when travelling, knowing that if needed you could download specific individual originals.
Where that option could be useful in for those users who are going to use LRCC only, not Classic. In that situation, the prime location of all synced assets is in the cloud, so prudence might suggest keeping your own copy of them locally.