Thanks for using the board planning tool and providing feedback. We will update the tool shortly to include all of the CPU versions currently available (N455, D425, D525, N450, D410, & D510). The peripheral devices available in the the tool are limited to those supported by the platform (i.e. DDR, USB, SATA, etc.).
Are there peripheral devices missing from the tool that this CPU & chipset combination support? If so, let me know and I'll be glad to make sure they become available.