@Galaa
CULLINAN I am also in same situation, I submitted biometrics via the app for my ILR application. My experience from previous application, Tier-2 which has been submitted in May and still not received HO decision, using the app takes a long time so you mean now situation is changed and there is no advantage for dual submission? How did you noticed that? Thanks in advance.
I meant dual submission makes sense for applicants who are waiting since March - Aug as they have been waiting for a long time.
The ones who submitted their docs via UKVCAS to UKVI, most likely their interim processing is done. Majority have benefited from dual submissions in that lot.
However, I do not see any advantage of dual submission for new applicants. Going for an appointment instead seems a better option.
Having said that, there is no guarantee for a faster decision on either route to submit biometrics. But if one has an
urgent need for a decision, I think one should test his/her luck via the appointment route.