I'm going to throw out another idea to everyone that don't want to necessarily upgrade to a 500 series board. I've got 3 ISY99's, 2 of which with the old series 3 board, that I went and upgraded to 5.2.0 and left the old zwave board in, disabled. Why would I do this?
Because earlier this year I moved all of my Z-Wave network over to OpenZWave on Home Assistant on a RPI4.
Im not going to lie, MIchel has done an excellent job over the years of building one of the greatest insteon controllers out there, period. While I decided not to go the polygot route, because I have so many other things that integrated so nicely, into Home Assistant --- I don't regret my decision going in that direction. The ISY99 has excellent HA support thanks to a few developers out there who a few months ago spent days and days of time building to the API's. Now my insteaon and zwave networks continue to operate as one, using automations under HA, rather than the ISY. And response time is as fast as if I were doing this all on the ISY. I admit, MIchel was so ahead of his time, that it's only recently that the automations system in HA can rival the ISY today.
If you decide to do this, look at the ISY as your insteon management system platform and HA as your state machine and build around that, I think you'll be pleased in what you find. Oh, and if you do want to keep Z-Wave managed by the ISY, HA will easily recognize the ISY Z-Wave devices correctly as well.
Brian