YES!! Thank you so much! Apparently, Adobe moved it to a different location. I've been looking EVERYWHERE for that. I thought I was going to have to edit five entire weddings - one file at a time. And yes, I actually did exactly that. Or at least that was the direction I was heading. Thank you again!
In case you are unaware: besides these options in 'Library', it remains perfectly possible to apply a Preset, or else any other kind of adjustment / change, IMMEDIATELY across a whole batch of highlighted images in 'Develop'. With immediate change to all of the image thumbnails (well, as fast as LR can do it).
There's no need to first apply change to one image, and then Sync (or Copy/Paste) settings onto other images, unless that is how you particularly want to do it.
And the images don't have to be highlighted in Grid view, they can alternatively be highlighted in the Filmstrip (which spans across all LR screens).
Just turn on "Auto Sync" at the bottom of the right hand panel in Develop. Now whenever you have more than one image highlighted, anything you do in Develop happens to all of those. This includes applying a Preset from the Presets panel, just the same as when you are doing that only to one image. IOW: you still carry out the precise same steps as when editing just one image, only these affect more than one image.
Lightroom is intelligent enough to deal properly with the situation where some highlighted images are Raw and others are JPG, so for example when adjusting White Balance which operates differently in these two cases, it will avoid weird accidental outcomes.
Note: if Auto Sync is then left turned on and you forget that it is turned on, Unwanted Outcomes Can Ensue. That's inconvenient rather than a disaster; a number of images may all require undesired steps to be rolled back in their History. There are tools and techniques to help with that, in the event that this happens. But given due care in turning Auto Sync off again, or else due care about whether multiple images are highlighted or not, Auto Sync is a wonderfully direct way to work IMO.
The biggest difference between Library / Quick Develop and the Develop mode, aside from applying a preset, is that the former's tools apply RELATIVELY on top of the prior varying settings of a batch of images. The latter's tools apply ABSOLUTELY: imposing one common new setting for that particular adjustment, onto all affected images. That's the kind of thing that gets recorded into a Develop preset.
So it may be found inconsistent and confusing to use Presets, which apply absolutely, from within Quick Develop in Library - which is otherwise all about making relative changes. Also Develop gives you that flyover preview of the potential effect of the preset on the current most-highlighted image (although not for any other highlighted images that would also be affected).