I've only scanned the paper (and I haven't read the previous comments) but, in terms of diagnostic testing, this is deliverable. The Government laboratories here in the UK get approximately £200 ($270) for a statutory LC-MS test [i.e. European Union food testing programs]; metabolomics instruments are basically an LC-MS/MS with a piece of fancy software (to interpret the signal).
This test needs to be tested on a larger sample group (try Vicky Whittemore) or your local government to deliver this.
Also, what's keeping the switch turned on, i.e. maintaining the hypometabolic state, is it a dodgy sensor or an underlying trigger (threat e.g. virus)? Again, try Vicky Whittemore or your Government to deliver this research.
If your in the UK where does this leave PACE, in the dustbin perhaps since its difficult to see how CBT etc could correct underlying metabolic issues. Ask you local politician for their views via a public forum (e.g. online).
This is good news, even if the benefits may take some time. Well done to those involved.