There's no such thing as a 'standard' retail commercial lease.
But, no. The lessor cannot charge the lessee the interest charges for the amount borrowed for the insurance cover.
The Retail Shop Leases Act is prescriptive in what can, and cannot, be charged. Lessors are permitted to charge lessees for outgoings, but the Act defines what outgoings are in section 7. The section provides:
"(3) However, lessor's "outgoings" do not include -
...
(g) payment of interest and charges on amounts borrowed by the lessor..."