I am not sure if I would have to use an external SSD drive on the RPI4, and in doing so, would that not be a slower option to run LE, as oppose to the Micro SD drive, which appears to be insufficient in regards to capacity?
An SSD will typically be faster than a micro SD card.
sdcards can be up to 1TB, so it's not limited in capacity, but I wouldn't recommend an sdcard that large.
An SSD is likely cheaper and faster at that capacity.