There should be no concerns using Joseph Long, I have followed it for many years now.
I also know a recent build carried out by him on a Kontrapunk C, where new parts are added, has blown the new owner/user of the Cart' away, it is claimed by the individual who informed myself, that it is now preferred in use over a much more expensive Cart'.
His Work is going all over the World and here in the UK, the Boron Cantilever with a FGS is a recommendation that can be seen regularly and those that adopt it are very complimentary in their appraisal.
I have become a fan boy of Ogura Vital Styli with a Beryllium Cantilever, I have heard this in comparison on same TT>Tonearm as a A/B to a similar Cart' but much more expensive from the same Brand/Family with a FGS added to the Cart' and I am more than happy with the choice I have made.
I have also A/B compared my Cart' in the same manner as above to a Cart' from the same Brand, with a Boron Cantilever and Ultra Polished Replicant Styli, and again am very pleased with the choice I made.