Yep, it will be hard to conduct. IMHO, it still possible to adjust slit experiment in such way, that slight increase in speed will break interference, i.e. at

Yep, it will be hard to conduct. IMHO, it still possible to adjust slit experiment in such way, that slight increase in speed will break interference, i.e. at speed X electron will behave like wave, but at speed X+1 electron will behave like normal particle.