simpleTom: I wonder if creating a ko with E4 (after the F4 - F3 - G3 sequence) is also a viable option. What do you think?
caranthir: Thanks for your question. Opponent (here I just say "White") could play like that if they had an advantage in threats and they had to try to squeeze points from somewhere. Now losing the ko is expensive for White too, because with just connecting at E3, White still have things like B6 sente, and if White instead plays the ko and loses it (having to finally connect at G5 instead), Black is comfortable with much bigger corner/side territory. So, it's good to keep in mind the possibility of the ko but in most cases I think it's not a practical option.
Thanks for your question. Opponent (here I just say "White") could play like that if they had an advantage in threats and they had to try to squeeze points from somewhere. Now losing the ko is expensive for White too, because with just connecting at E3, White still have things like B6 sente, and if White instead plays the ko and loses it (having to finally connect at G5 instead), Black is comfortable with much bigger corner/side territory. So, it's good to keep in mind the possibility of the ko but in most cases I think it's not a practical option.