1. Introduction

2. ESO SupJup Survey

3. DENIS J0255  
3.1. Observations & Reduction  
3.2. Retrieval Framework  

4. Results  
4.1. Bulk Properties, Temperature & Clouds  
4.2. Detection of Molecules  

5. Discussion  
5.1. Validity of Cloud-Free Solution  
5.2. Chemical Quenching & Vertical Mixing  
5.3. Formation History & Isotope Ratios  

6. Conclusions