The person who knows how it works is the risk

There is one person who knows how the tracker feeds the CVR, which fields actually matter, and what to do when the export fails. They are capable and helpful, which is exactly how the dependence grew: nothing ever forced anyone to write it down while they were there to ask.

A system held in one head is a system without documentation, and an undocumented system cannot be handed over, checked or fixed by anybody else. A holiday becomes a pause; a resignation becomes a rebuild. The cure is not hiring a second expert - it is making the system the business's: documented, familiar to a second pair of hands, changes reviewed so the knowledge stays put when the people move.