This update is part 1/4 of the Format update.
Part 1 changed the way config files work, so it’s important to use the converter if you don’t want to lose your config files, part 2 will change the way alts work (and there will be a converter as well), part 3 will change the way keybinds work, so that you can bind commands to keys instead of just mods, and finally part 4 will change the way custom AutoBuild templates (which are now called templates instead of structures) work, so that you can use multiple custom templates or even delete the default ones.
I want to get back into the habit of releasing a Wurst update every Friday, so Wurst v1.6 might already come next week.