Crazy to upgrade whole home Caseta to RA3?

Where this came from: this question was asked on r/Lutron — not here. We answered it there, in public, and this is that answer.

You're not insane, but I'd split this into two decisions, because one of them is worth doing and the other mostly isn't.

The shades are the easy call. Do it. The noise you're hearing from the Shade Store units is the motor and the tube, and no amount of system upgrade fixes that — you fix it by buying a quieter motor. What you may not realize is that you don't need RA3 to do it. Lutron's battery shade line pairs to the Caseta bridge you already own, so you could replace those five or six rooms tomorrow, keep everything else as-is, and they'd show up in Home Assistant through the same integration you're already running. If some of those are large or in awkward spots I'd look at wired instead of battery, but that's a per-opening conversation, not a system conversation.

Ripping out 90 working dimmers and switches to get to RA3 is a much harder sell, and I'd tell you no if the reason is that the switches look nicer. The Caseta Diva dimmers (DVRF-6L) have the paddle look and get you most of that aesthetic for a small fraction of what a whole-home RA3 conversion costs, and you can swap them a room at a time out of pocket. The real reason to go RA3 is keypads — engraved multi-button keypads by the door instead of a wall of Picos in visors — plus one system instead of two hubs (Lutron's RA3 sheet: up to 95 devices per processor, 200 per system), and proper scene programming. If you want keypads, that's a legitimate reason and I'd support it. If you want better-looking dimmers, it isn't.

On the exhaust fans: I wouldn't assume you've outrun the system. 90 devices across two Pro bridges is not a taxed network. What matters is where that timer actually lives. If it's a schedule or auto-off in the Lutron app, it's the hub running a clock and firing a single off command, and if that packet doesn't land the fan just stays on. If it's a Home Assistant automation, it's HA firing at the bridge and the same thing applies. If there's an occupancy sensor involved, it's the sensor's own timeout and nothing to do with the hub at all. Those are three different failures with three different fixes, and one of them costs nothing. Worth pinning down before you spend money on the theory that the system is overloaded.

If you do go RA3, two things to ask the dealer before you sign anything. First, budget for the dimmers being replaced: Lutron's RA3 compatibility FAQ lists RadioRA 2 and RA2 Select devices as compatible and no Caseta devices (https://support.lutron.com/us/en/product/radiora3/faqs/backwards-compatibility/is-radiora-3-backwards-compatible-with-radiora-2-and-ra2-select-which-devices-are-compatible-and-which-are-non-compatible). Second, ask up front how you get access to the system after they leave: who is dealer of record, whether you get the project file or a client-level login, and what it costs to have a button relabeled in two years. Plenty of installers are fine about this and some are not, and you find out at the worst possible time. Given that you run Home Assistant, also confirm with them how keypad button presses come through to HA, because that's the part people assume works and then discover they've lost.

If you list out what's on each of your two bridges in the thread, it's easy to say which parts of this are worth paying for and which you can do yourself. Disclosure: I'm a Lutron dealer, so I have an obvious interest in you buying Lutron gear, which is part of why I'm telling you not to replace 90 working dimmers.