Post-op PSA test coming up

My husband's post-op PSA test is coming up in 2 weeks.  In the UK they do not do ultra-sensitive PSA tests.  The standard PSA test goes down as low as 0.1.  I am sure I may be able to find a private clinic that may do the ultra-sensitive testing.  Is it worth doing this ?  The doc has said that no further treatment would be initiated unless there was a PSA reading of 0.2 or higher.  Seems to me that this could be another delay in the right treatment ?  Surely it is better to observe any small changes in PSA from 0.01 rather than starting from 0.1 ?  Anyone have any opinions or advice on this ?