Devices for loading intravascular treatment devices into a sheath and associated systems and methods are disclosed herein. A sheathing tool may include, for example, a first channel extending to a first opening, the first channel configured to receive a treatment device in a constrained state therethrough. The treatment device may include an elongated member and a first element and a second element at a distal region of the elongated member. The second channel may extend to a second opening, the second opening surrounded by a sidewall and configured to receive the treatment device in the constrained state therethrough, wherein the second opening is spaced apart from the first opening by a gap, and wherein a length of the gap is great enough to allow the first element to self-expand over the sidewall while the second element generally maintains its diameter in the constrained state while crossing the gap.