The Smartlock Slimline Universal is still the only lock I've found that meets all criteria.
At £300 I didn't buy one (yet) and TBH I haven't been looking recently. Other household bills have had to take priority, not least the gas & electricity which was on a darned good fixed deal at £116/month but will now be £240/month. Thank god for the Tado smart TRVs, without which it would be even higher.
