I think an under-explored use of BlocklProp is for an excursion from Scratch. Scratch is common but the problem I see is that it is another hour of kids sitting in front of the screen. In my Scratch unit I have groups rotate out for a couple weeks to a table with S3's. After explaining how to use the client, I say BlocklyProp is like Scratch but with new blocks that are specific to hardware. Then I explain the difference between motion blocks that are a specific time/distance and those that continue until explicitly ended. Away they go.
Tip: Divide their S3 study into two levels of 3 hours each. Start them off with task of drawing traces using loops. Then level 2 go to tasks of sensing using branching. That order has worked better than starting with the enclosed poster of sensing projects. Using 2 short units gives me more flex for rotating people between Scratch and S3.
I have more materials and suggestions here that I use in my educator workshops at the community college