It's true that the traditional units are still in use. Mostly in rural areas and, local markets and small stores in cities.
Although not all the unites from smallest to largest are all in use. Mostly middle parts of those unit are in common use. e.g., only Htwa (length from tip of your thumb to pinky finger), Taung (length from your fist to elbow), Lan (length of stretch of both hands) are in common use of length. Same goes to weight and volume as well. Even local people don't know the correct measurement of smaller and higher ones.
I have created a converter app for that (Burmese language): https://play.google.com/store/apps/details?id=com.eimaung.th...
Imperial units are also in used, such as mile in highway roads, inches to measure clothes, feet to measure building, pound to weight foods, etc... Government is trying to migrate metric system (I think there was an official statement), but without proper plan, no progress so far.
So, you will see all three of systems are in use in mixture of here and there. It's so mess-up. We have serious standardize problems. Measurements is not the only one. There is a similar story with character sets and encoding that seriously messing up Myanmar language on computer.