Do bees "waste time" on certain plants?

No, I would have to say I don't think they waste much time. I'm sure they will switch to the better plants as they start to produce nectar. They may need more pollen right now to raise brood. They will often times work several different plants at one time. Watch the foragers as they return to the hive most of the time in the spring you will notice several different colors of pollen coming in.

Stuart, the bees turn that pollen into brood. I would not cut down any early pollen source. Bees do well with a variety.

Both are correct. Depending on what the hive needs the workers will switch between pollen and nectar
plants. When they are raising broods they collected many different varieties from the pollen plants. Then
switch over to the nectar plants for honey storage on the flow. I would just leave everything as is for now.
Maybe after the bloom you can mow them over.

Until I get better at gathering nectar than my bees are. I will leave such decisions up to them.

Well stated Daniel. Just what I was thinking, stated better.