An x-ray all-sky monitor based on a lobster-eye focusing optics concept is a very promising satellite for the future astronomical mission. The angular resolution of the optics based on Angel's geometry, implemented as an array of square pore channel pates is, in theory, limited by the physical size of individual channels. In practice, the metric uniformity, in particular channel misalignment, and surface roughness of the channel plates are the prime factors limiting the efficiency and resolution of the focusing optics. Most of the methods to test the metric uniformity suggested earlier allowed to study the quality of the pates only in local areas. We suggest another method of estimation of the global uniformity, and in particular the multifiber misalignments, over the entire plate area based on moire interferometry. It is shown that for conventional MCP with 60-pore multifiber diameter this technique in principle can detect the multifiber angular misalignments and twists with an accuracy of about 1.2 mrad. The channel long axis misalignments may also be measured with accuracy of 35/L/p mrad, where L/p is the channel length to interchannel distance ratio. We believe this technique is a powerful tool for the preliminary selection of channel plates to be used in focusing optics.