OK I finally managed to do it, apparently you can jump (sometimes) while on the ladder. But the ladders are definitely quite janky and confusing. At least I can now try more!
Thanks so much for the kind words! The ladders are definitely janky and I struggled implementing them, so it's not your fault lol. They are consistent though, basically climb to as high in the ladder as you want and stop. Then press W again and you'll get a hop and then you can control the direction you go. You can also get off ladders by pressing A or D, which makes you dismount without getting the hop. Hope this helps if you ever decide to come back, thanks again for checking it out!