When exporting in the recipe there needs to be a function to resize the export by a megapixel value. Eg, I shoot a 61 megapixel camera for one client they like 5 megapixel images delivered with a 5x7 crop. Lightroom as an ability to do this you just select megapixel in the output size and enter the number of megapixels and it will resize the image accordingly as it exports.
Current workaround
I have set the short edge to 1920. With the 5x7 crop this seems to work