Is it possible to submit VAF4a supporting docs by courier after bio metrics
 

This is our situation:
-We are apply for UK family settlement (form VAF4a online)
-My partner and children reside in the Solomon Islands.
-They are travelling to Fiji to give bio metrics.
-They don't have Tuberculosis test certificates (required) so are booked into an approved clinic in Fiji (there are no approved clinics in the Solomon Islands).
-The results of the TB test will take two to three weeks to come in.

This is our question:
If they give their bio metrics (at VFS Global) before the TB certificates are issued, does anyone know or have experience in what may be possible with regards to submitting the TB results at a later date? Is it possible to give the bio metrics first and then submit supporting documents by courier for example?

Unfortunately they cannot remain in Fiji to wait for the TB test results and then make the submission. Making a second trip to Fiji is not practical given the cost and disruption to studies and work.

Many thanks