I'm just gonna post this tutorial here:
To create a dynamic dropdown menu, you have to create a new input value, and select scripted:
To add values, drag when [ V] menu clicked::control hat into the block editor (one of the most cursed actions you could possibly do in Snap!), and the dropdown in the hat will populate with all of the scripted option values. To add options, you must append report (list [option 1] [option 2] @addInput::lists) to the end