Correct processing of reverse strand VCF insertion alleles

A corner case when processing VCF variants to a reverse strand sequence.
Example: BRAF is ENSG00000157764 GRCh38:7:140719327:140924764:-1
Insertion G,GTATT at position 140924424 of genomic sequence
   G maps to (complement) C at position 341 of transcript ENST288602, position 280 of CDS.
   genomic (forward strand): G (insertion) TATT T
   could be shown as
   gene/transcript (reverse strand complement): A (insertion) AATA C
i.e. a reverse complement insertion on the _preceding_ position?
Currently Jalview renders as C,AATAC which makes no sense (start base of insertion should match reference base).