Boost performance by allowing using Smart Preview for editing

[Arne Rudi]

Using Smart Previews for editing is many, many times faster than using the original RAW file. When you generate Smart Previews and then disconnects the drives containing your RAW files, Lightroom will use the Smart Preview for all editing in absence of the RAWs - which is 10x faster than using the RAW (when viewing at 100% zoom or above). 

Suggestion: Make the "Original Photo" icon under the histogram clickable, so we can select between editing on the Original Photo and Smart Preview.

[JohanElzenga]

The opion to use smart previews (even when originals are available) has been in Lightroom Classic for many years! Go to Preferences - Performance.

[Ian Lyons]

Also worth mentioning that when we zoom into 1:1 or larger, then LrC uses the original full size image (if available) rather than the smart preview.