I'm not condoning leaving the washers out but I've got a V6 GTV that's probably had them like that for over 3 years/12k miles that shows no real signs of wear, no sloppy uprights & drives fine!??
You may well be right, I had to say that, as there is 'theory' and 'the real world', If the car is passing MOT tests and there is no play then it must be fine. More than one way to skin a cat!! It's really up to the mechanic doing the job to make the decisions.
The only advice I would give is do not use excessive force when fitting these bushes, no lump hammers or hydraulic jacks. Especially around a cast ally subframe. Cast aluminium will not bend. that's forged aluminium. It's very brittle and when subjected to loads that the assembly is not designed to withstand it will crack. Once everything is bolted together and torqued up its probably fine. the dangerous bit is during the assembly.
Cast metal is fine when used in the correct application, It's to do with the choice of material and the design/purpose. For example a piece of string is fantastic for hanging things from the ceiling but it makes a pretty crap table leg.
The inner springpan LUGS are not designed to be forced apart or together. You can prove this by removing the arm complete with bush, refit the bolt and tighten it up. It WILL CRACK!! DO NOT DO THIS!!
(Just trying to explain)
The bush centre steel insert is there to prevent the lugs from distorting inwards when the bolt is tightened up, it has no other purpose. If it is too short, due to wear on the subframe etc. the lugs will distort inwards and possibly crack. if it is too long it will bend the lugs outwards. And even if it doesn't crack on re-assambly an excessive load/stress will be present that could cause a break later on. (this can happen with OE bushes if there is wear on the s/frame).
So go easy, No force, A few taps with a 2lb hammer Max. If the s/frame is worn, get a new one or get it TIG welded and dressed
I think Powerflex have sorted the inner bush problem out . but there may still be old stock out there. Now they should fit fairly easily.
If you have any problems e mail them from their site and ask advice. They are very, very good.
There's nothing wrong with hacksawing/burning old bushes to remove them, it just takes longer, but maybe not as long as driving the arms to a garage leaving them there and then picking them up the next day, and of course paying them.