Round up in fractional zooming

[fly2279]

I was wondering if there could be an option to round up to the next higher zoom level when fractional zooming if over the integer zoom level, instead of rounding only if at or over the .5 level. i.e. Aerial Imagery would be more clear if using tiles from zoom level 16 and scaling the image down instead of scaling a zoom level 15 tile up at zoom 15.4.