sirona strategy
Sirona is probably trying to convince the buyer by the fact that 3% Deoxyarbutin (DA) is not considered safe -in EU at least- because of HQ release. Is TFC-1067 a more effective lightener than DA? We do not know their head to head lightener efficiency comparison. But as TFC-1067 is safer (no HQ release) one can use it longer to get the desired effect.
Here is the EU report. There are useful references given in it.
https://ec.europa.eu/health/scientific_committees/consumer_safety/docs/sccs_o_183.pdf