Given the balance sheet data, we can compute the key metrics needed to assess the company’s position relative to the 15% hybrid cap.

First, we identify total adjusted capital (debt plus equity).

**Equity** at 2023-01-01 = 2,390,570,000 EUR.

**Debt** includes short-term and long-term financial liabilities (excluding other financial liabilities that might not count as core debt, but using the main line items provided):
- Short-term financial liabilities: 142,437,000 EUR
- Long-term financial liabilities: 6,402,913,000 EUR
Total debt = 142,437,000 + 6,402,913,000 = 6,545,350,000 EUR.

**Total adjusted capital** = Equity + Debt = 2,390,570,000 + 6,545,350,000 = 8,935,920,000 EUR.

**S&P’s 15% cap** on hybrid equity credit = 15% × 8,935,920,000 = 1,340,388,000 EUR.

This is the maximum amount of hybrids that would receive equity credit. The question asks to what extent the company *should* utilize this cap. 

Looking at the company’s capital structure:
- Debt-to-equity ratio is high (around 2.7x).
- The interest rate environment (provided swap curves) shows that rates have risen significantly in 2022 (10Y swap from ~0.05% in 2021 to ~1.93% in 2022), making hybrid issuance more expensive compared to the prior low-rate environment. 
- The company already carries significant debt, and adding hybrids up to the full cap would increase leverage and interest costs at higher rates. 
- However, hybrids can provide equity credit without shareholder dilution, which is valuable for a utility-like entity with large ongoing investment needs (shown by the high capital expenditure on intangible assets). 

Given the cost of hybrids has risen (corporate bond yields up from 0.73% to 1.085% between 2021 and 2022, and sub-sen non-financial IG yields up to ~2.295%), fully utilizing the 15% cap might be overly expensive and aggressive. A moderate utilization (e.g., 50%) would balance the benefit of equity credit for credit ratings with cost efficiency, but the phrasing "to what extent *should*" suggests the company should take advantage of a reasonable portion, not necessarily the maximum, given market conditions and balance sheet prudence. Still, the 15% cap is a limit, not a target; 100% utilization would mean issuing ~1.34 billion EUR in hybrids, which is a large new issuance for a company of this size and might pressure coverage ratios given rising rates.

Given the rate environment and already leveraged balance sheet, a conservative to moderate approach is best—hence 50% utilization (25% or 50% are the likely conservative-to-moderate options; 50% seems a measured extent).

<answer>50%</answer>