What we do at its suits our home programme size and staffing level is to chemically disinfect every 6 months and that's it.
Our incoming water is soft at ~60ppm so we don't use softeners. We do get some reduction of flow some times but at that point we swap the RO out and give it an overnight citric soak which usually recovers it.
We're 95% on the Aqua Uno cold disinfection model so couldn't heat if we wanted to. I wouldn't say we get as long as you out of a membrane however I suspect that is more to do with chlorine damage due to patients not changing filters when they should. Membranes for the Aqua Uno Cold can be sources for around £350 so not too bad. I believe the Aqua Uno Hot membranes are about £2k though. I have no experience on the WRO300H unfortunately.
We have also stopped testing for micro now on home patient RO units backed up by considerable historical data. Some may say that's controversial however when you're changing diasafe filters evert 3 months and only obliged to test every 6 months anyway any sample is only as good as the moment it's taken. Symptoms from a micro infection certainly wouldn't take 6 months to present themselves.
You don't have to sample fluid produced by the NxStage device and the PAK in that is also changed every 3 months like the diasafes/ultrafilters on most machines.