This article reports the design of a versatile multislit-based very small angle neutron scattering (VSANS) instrument working either as a dedicated instrument or as an add-on for any small-angle neutron scattering machine like the proposed SANS instrument, SKADI, at the future European Spallation Source. The use of multiple slits as a VSANS collimator for the time-of-flight techniques has been validated using McStas simulations. Various instrument configurations to achieve different minimum wavevector transfers in scattering experiments are proposed. The flexibility of the multislit VSANS instrument concept is demonstrated by showing the possibility of instrument length scaling for the first time, allowing access to varying minimum wavevector transfers with the same multislit setup. These options can provide smooth access to minimum wavevector transfers lower than ~4X10^-5Å^-1 and an overlapping of wave vector coverage with normal SANS mode, e.g. with the SKADI wavevector range of 10^-3–1.1 Å^-1. Such an angularly well defined and intense neutron beam will allow faster SANS studies of objects larger than 1μm. Calculations have also been carried out for  radial collimator as an alternative to the multislit collimator setup. This extends the SANS Q range by an order of magnitude to 1X10^-4Å^-1 with much simpler alignment. The multislit idea has been realized experimentally by building a prototype at Laboratoire Leon Brillouin, Saclay, with cross-talk-free geometry. Feasibility studies were carried out by making VSANS measurements with single- and multislit collimators, and the results are compared with multiple-pinhole geometry using classical SANS analysis tools.