Shrink-swell soils are a hard soil to make any type of measurements in because of all of the challenges they present. The key is to not create any preferential flow paths artificially by putting walls up that the soil can shrink away from. A good type of lysimeter for shrink-swell soils is a controlled tension lysimeter with only a suction plate at the bottom. You will get accurate measurements of flux rates without introducing any preferential flow paths. Any type of lysimeter that uses walls to encapsulate the soil is probably not going to be optimal for soils with a high shrink-swell capacity.