Most certainly you could manage a glycol chiller at a warmer temperature as well as the keg cooler. Be aware that the crowd you aim to please may be minimal compared to the market conditions that exist at retail today. We all are aware that certain products are specified for consumption at a higher temperature. The problem is that the average consumer in the U.S. just does not like warm beer.
Should a retailer set up their system to accommodate the different temperature specifications? By all means. Will they? Probably not.
As to the "most brewers" you refer to. Is this the temperature that they recommend based on their palate or have they spent tons of money as the "swill" brewers have to determine the optimum conditions desired by the consumer?
If you do attempt to dispense at a higher temperature, you will need to know the gas content of the product. Thus, this will determine the counterpressure required to maintain this gas content.
Scott Zuhse, Instructor
Micro Matic Dispense Institute