It’s really no more time consuming than any other letter. It might look a bit bigger, bit it’s just two loops, which is a very quick and natural movement that you’ll be doing a lot if you write in cursive.

It’s more about following the flow of the lines than the size of the letters. Each letter should feed into the next one, so you’ll barely need to take your hand off the paper for the same word. Even if you choose to make an especially “high f”, that’d still take less than a second of you know what you’re doing.

(Also, as has already been pointed out, second one is a J)