Yes… I also found Logitech’s activities not so smooth, and your sequence example is the same experience I had. On my U1, I actually Did set up “devices” to contain the native button setups (eg: Sony TV, and then duplicated to set up a macro programmed set of multi-device steps (eg: TV + DVR). My macros refer back individual the individual devices while I use the combined device for programmed steps. Not sure if that is correct but it worked well for me. Kind of like having multi device “activities” using individual “devices”.

I was able to by just using the FireTV icon at the top of the iPhone app. See video. A bit confusing bc the icon is FireTV and not TV stick, but worked for me. See in video