We haven’t yet posted documentation for v1.4 - that will not be available until the products begin shipping to customers in May.
Generally speaking, v1.4 will be a more minor improvement to the design because we’re focusing most of our resources on the changes needed for the XL device, software development, and ramping up our supply chain and warehouse capabilities. Something we are hoping to include in v1.4 is the next iteration of Farmduino as well as a revision to our custom electronics box.