Multiple questions about Insteon scenes

After successfully setting up Home Assistant and having used it for close to a month now, I’m ready to start polishing some of the rough edges! One of the issues I’m seeing is that Insteon devices in Home Assistant’s scenes, automations, and scripts turn on sequentially rather than simultaneously. This is covered in another topic, and it sounds like the workaround is to have Home Assistant activate scenes that are programmed into the PLM. So I have a couple of questions on this…

  1. Is that all still accurate and did I understand correctly? Or is there another workaround for getting Insteon devices to activate simultaneously?
  2. Are the scenes stored within the Insteon PLM synchronized with the scenes in Home Assistant’s configuration? Or should I be considering them as separate things, “Insteon Scenes” and “Home Assistant Scenes”?
  3. If they’re not synchronized, is there a way to program scenes within the Insteon PLM using Home Assistant?
  4. Is there a way within Home Assistant to view a list of the scenes programmed into the PLM? From what I’ve seen, they’re group numbers, but I have no clue what they would be. I suppose I could go into the dev tools and just plug in numbers sequentially until something happens.
  5. If Insteon scenes and Home Assistant scenes are separate things, and there’s not a way to view or program the PLM scenes from within Home Assistant, what’s the best way to do that? The only method I know of is hooking up the old computer and software I’d previously used for home automation (a Mac Mini running Indigo Server.)

For posterity, I’ve found some answers.

  1. Yes, this is still accurate and seems to go beyond just Insteon. See Are HA scenes capable of turning all devices on at the same time?
  2. Although I never got a definitive answer on this, I’m pretty certain Insteon Scenes and Home Assistant scenes are separate things.
  3. Not that I’ve been able to find.
  4. The closest I’ve found here is viewing /config/insteon_devices.json in the file editor. Here, you can at least see what group numbers are used by devices to help determine what numbers you could try pinging with Home Assistant.
  5. According to the documentation, there are some command line based tools such as Insteon Terminal and insteon tools which is part of pyinsteon. They also mentioned the discontinued HouseLinc software for Windows for the less technically savvy (me.) I think these or Indigo are my best bet.