There is no "Persistent User Interface" option in tvheadend, I think you mean "Persistent view level". The persistent view level only controls what is shown, Basic shows the most common options and so on. What it doesn't do is remember custom changes.
Custom changes are remembered using a cookie stored in your browser, if that expires or gets deleted it'll return to default.
No it isn't ideal & yes the interface needs a refresh but sadly no one has the time to do it.
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> Apparently Tvheadend is 'special' and doesn't have to, but I'm guessing the distinct lack ofresponses means nobody cares very much. Pity I'm not a developer or I'd have a crack at fixing it myself.
Not true the lack of response is due to limited time, retorts like this helps no one :(.
There is absolutely nothing stopping you both getting involved, in fact it would be most welcome.