Seeking creative structuring ideas for partial seller-financed buyout (Ireland)

Hi all — I’m deep into due diligence and legals on an acquisition of a niche distribution business in Ireland. Enterprise value is around €2M for a €500k EBITDA company. The structure so far: 70% acquired upfront for €1M cash, funded via bank debt (€840k) and 500k equity. This covers : 1m upfront, 160k of operational cash to inject into the business, 60k estimated closing costs, and some money left for the Y1 Earnout (the rest coming from cash flows). The Year 1 €400k earnout can be paid over two years (50% payable at end of Y1, 50% at end of Y2). It ranges from 300k to 500k depending on Y1 profits. A 30% minority stake remains with the seller, with a fixed call option at €600k exercisable by end of Y3. The seller has been flexible and effectively providing 50% vendor financing, but he’s now looking for some form of security (I undestand say €150k) to feel comfortable about the deferred 30% payment, the rest likely to come from extending the existing credit facility. Under my bank loan terms, I can’t give a personal guarantee, so I’m exploring alternative ways to offer limited security. Has anyone solved for this before? Would welcome any practical ideas or examples on how to secure part of a deferred consideration without breaching senior debt covenants or giving a PG.