I take it that forge dont make a decent revised BOV that wont split and wont need to be sorted all the time?
As for relocating the original is this quite a lot of work? Im not hugely experienced on engines, more simple mechanics and dont want to start messing around when I dont know what im doing.
Forge do both a Blow off valve and there own version of VW's recirculation/Diverter valve. There is some small periodic maintainance associated with the Forge valves.
The relocation job can be done with oem parts from the dealer and its not a big job, heres a link to a fella who did his own version of the relocation - this is the same setup found on the KO4 engines.
http://www.mk5golfgti.co.uk/forum/index.php/topic,17736.0.html
Your not making drastic changes to the way it works your just moving it further towards the intake manifold and blanking off the old dv location.
If you got a garage to do it its probably an hours labour but once its done you will now have easy access to both the Diverter valve and the PCV system which as we all know can be a common problem on these cars.
I take it with the forge dump valve will require cleaning or is it something more than that? Seems strange that if it is an uprated part then it takes more looking after than the original.
Im quite tempted to run a stage 1 remap with the original and just keep and eye, is there any signs that the valve is going wrong? Things to spot??
I believe the Forge Recirc valve needs periodic greasing.
Your valve may be torn now, if you have ramps or stands you can look under the car and see what revision you have and check it at the same time. Either way failure is likely to increase with a remap - but dont let a torn DV stop you remapping. If anything replace it when you have it mapped.
Its difficult to say when you have an issue as the valve doesnt so much fail in the sense its failed to open or close properly its the leaking boost which will reduce performance and I have found that it does have a reasonable impact on peformance particulary in holding boost.
Other than periodic checking the only reliable method of measuring the problem is with a boost gauge so if you have one of those fitted you will be alerted to potential issues earlier.
Sometimes this code may be thrown:
16683/P0299/000665 - Boost Pressure Regulation: Control Range Not Reached
But this code could mean several issues with the turbocharging system so its one of a few possiblities.
Best thing to do is periodically check the DV and lament VW's designing!