Okay, this might be ... just semantics ...His burdens are for sure, light :)
Somewhere in the OT, God told them because they called His Torah or Instructions "a burden", they were in trouble. I don't remember where, or if they got punished for that... perhaps it was also where they grumbled? , and even though they did do what God said to do, they were punished, because they grumbled...
Then, in the NT,
Jesus says "His commandments are NOT A BURDEN (i.e. not burdensome) , but light and easy" ...
i.e. perhaps a light burden - but not with the thought of being actually a burden , not at all a hardship or difficult....
So the ... nuances ... are , here, just for the 'back burner', ? , maybe not a main point, yet maybe so, maybe an important one...