What are the limitations and potential drawbacks of running a single chainring setup on the Cannondale Topstone AL 105 for gravel riding, and how do these compare to the benefits often cited by proponents of 1x systems, such as reduced weight and improved simplicity, in terms of actual on-bike performance and versatility. Specifically, do the gains in reduced mechanical complexity and improved durability outweigh the potential losses in terms of reduced gear range and increased stress on the remaining components, and how can one determine whether a single chainring setup is the right choice for their specific riding style and terrain. Are there any specific considerations or modifications that can be made to the stock Topstone AL 105 to make it more suitable for a 1x setup, such as upgrades to the crankset or derailleur, and what are the implications of these changes for the bikes overall performance and character.