Transformer for Ring Video Doorbell Pro 2

I live in the UK and have a traditional 12V hardwired doorbell chime wired up to a [Jeani JBT012 transformer](https://jeani.co.uk/product/jbt012/) (4-8-12V 50/60Hz 1A).I’m thinking of buying a Ring Video Doorbell Pro 2, which requires a 16-24 VAC, 10-40 VA, 50/60Hz transformer. If I replaced my incompatible transformer with the 24V DC, 0.42A, 10W DIN rail transformer (supplied with the [RVD Pro 2 – UK version](https://en-uk.ring.com/collections/video-doorbells/products/video-doorbell-pro-2)), I would have to bypass my 12V hardwired chime and use a wireless chime instead.I would like to use a traditional hardwired chime rather than a wireless chime. Seen as I cannot find a 24V chime, presumably a RVD Pro 2 would operate correctly with a compatible 16V transformer and 16V hardwired doorbell chime?If yes, then…1) Would the Honeywell D117 Home Ding Dong Classic chime be compatible? [PDF suggests it’s 16V compatible](https://m.media-amazon.com/images/I/71snxY-NshS.pdf).2) Can anyone recommend a transformer that will be compatible with a RVD Pro 2 and a 16V doorbell chime?3) Would the [Protek BT8-16 Bell Transformer](http://protekuk.co.uk/16V-8VA-2-Module-Bell-Transformer-BT8-16) (16V, 8 VA, 50/60Hz) be compatible? Despite an 8 VA rating being outside Ring’s 10-40 VA range, I’ve seen people on the internet say it works with Ring’s doorbells, but also some say they don’t!Also, despite Ring specifying a 10-40 VA transformer is compatible, I’ve read 30 VA is recommended. So, what are the pros/cons of 10 VA compared to 30 VA?