[FrankB]

Here in the US, they were only used in radios and some "El Cheapo" amps here.
I have never seen one used in a TV set, (Excepting the combo sets, of course) at least in my 45+ years of repairing.(But they did tend to throw the odd designed set in once in a while too).
Since the filaments were series, in the AA5's, and cost was a concern, the bean counters wanted to save every where they could. So the 35Z5 and 35W4 were used as the most common rectifiers in the AA5 sets. Adding a power TX for safety and a fil. winding were out of the question, production cost wise, for most Mfgr's.

IIRC, there may have been other rectifiers also that used the split fil. , but none spring to mind immediately.
When the fil. in the pilot lamp died, an excessive amount of current flowed through the rectifier's remaining fil, and greatly shortened the life of the tube.
In fact I remember some tube mfgr's refused to accept defective new rectifiers of those types, unless you replaced the pilot lamp at the same time as the rect. tube!