I'm planning on switching to using PLA+ and am slicing a few models, I'm wondering what the typical optimal temperature for PLA+ is with the Ender 3.
Usually the filament spool will have a range of temperatures for the best nozzle temperatures and bed temperatures to use. To answer your quesstion there are several considerations.
Not all PLA's are the same and that is probably even more so with PLA+. That is where the temperatures written on the spool come in handy.
Optimum temperatures will vary for different printers.
Optimum temperatures will vary depending on the print job: large versus small; thick versus thin; short verses long; etc.
Optimum temperature will vary depending on print speed, as well as enclosure or lack of, and air circulating through enclosure with fans.
You may need to tweak settings to get the optimum print.