Corrections to UK Naturalisation Application

I submitted my application online (Form AN) and uploaded and submitted my documents on the TLS website, which you can't amend afterwards.

At 4am, I realised I had completely forgotten to include my short visit to see family in Ireland last month. We went by ferry via Holyhead-Dublin and back. They looked at my passport in the ferry booth, but I have no stamps. The only evidence I have of this trip is the ferry tickets and hotel stays en route.

I've booked a new biometric appointment and paid for scanning so I can upload those ticket purchases with an amended covering letter.

My question is for those who have been in this same situation. Was there any issue adding extra documents at your biometrics appointment, if you self-uploaded everything else in advance? Do they take into account what you've uploaded already i.e. I don't need to upload everything again at my appointment, do I?

Does UKVAS start looking at your application before you've done biometrics, or only after you've attended the appointment?