Given VERBUND AG’s 2022 financials, the company shows strong earnings growth with EBITDA rising to €3.16bn and Profit Attributable to Owners of Parent €1.72bn. However, from a balance-sheet perspective, debt levels and cash flow dynamics suggest meaningful capital needs ahead, including sustaining large-scale electricity generation and grid investments in a regulated utility context. Key observations:

- Total assets and equity remain substantial, but noncurrent liabilities and current liabilities indicate ongoing funding requirements. Equity declined in 2022 from 2021, while comprehensive income improved, signaling some volatility in non-cash items but solid cash generation from operations (Cash Flows From Used In Operating Activities €2.02bn in 2022, up from €0.98bn in 2021).

- Hybrid instruments are typically used to bolster adjusted leverage metrics in a capex-intensive, regulated utility with high investment needs and to preserve investment-grade credit. The S&P cap allows up to 15% of total adjusted capital for equity credit on hybrids; current starting point of outstanding hybrids is not provided, but the policy requires considering a path to 15% max.

- The company reported substantial capex activity (Purchase Of Property Plant And Equipment etc. €1.091bn in 2022-2023 period), and noncurrent liabilities, including noncurrent financial liabilities, rose to €2.844bn by 2023. The business is clearly capital intensive, with ongoing investment needs that could stress leverage if not matched by cash flow.

- Market and interest-rate environment: Swap curves in 2022 show higher rates (5Y ~1.7-1.8%, 10Y ~1.9%), suggesting higher cost of debt funding if no hybrids. Hybrids could improve balance sheet resilience without immediate cash interest burden, given equity credit.

- Regulatory nature of VERBUND (regulated utilities) supports a favorable regulatory framework and stability, which bodes for lower risk in maintaining debt capacity. However, the elevated depreciation and impairment numbers (Impairment Losses €197.8m in 2023 year; large valuation effects) indicate volatility in earnings that could affect credit metrics.

With these considerations and following the checklist:

- The moderate-to-high capex intensity and need to maintain investment-grade trajectory point toward a need for capital structure optimization, but not an urgent transformational requirement unless capex accelerates.

- A level around 7.5% would meaningfully improve adjusted leverage without imposing excessive cost of debt, and aligns with a moderate refinancing/acquisition pace scenario.

- 11.25% or 15% would be more appropriate only if there is very high capex need or transformational program.

Therefore, recommended: 7.5% of total adjusted capital.

Final answer line: <answer>7.5%</answer>