Example 1: 

Assume a quantity equation  where we substitute  (and probably other parameters with units) to obtain a numerical result.
After some simplifications the result is

A result in this form is the most frequent physical quantity equation with units in use:

A physical quantity denoted by the name  that is equal to a numerical value times a physical unit.

In this form it is also the shortest way to define/name scientific constants, scientific and engineering parameters, and results for variables/unknowns.  

To better interpret the above result a conversion to micron is desirable. This unfortunately does not work with the context panel. Alternatively one could think of mapping a command onto the equation.
(Mapping a command is a good practice to threat the left-hand side and the right-hand side of an equation equally.)

This however does not work, since the left-hand side does not contain the dimension length, but only the name  of the physical quantity.  

A way to convert is:

For a single result this might be acceptable, but for a list of results this not practical.

In any case not being capable to apply to an equation the same operation to both sides bares the risks of introducing errors.

Example 2: 

More complicated are results of this kind

A way to convert this to :

This is too complicated.

Instead, eval with a manually entered conversion can be used for this

However, this is old style: The way we had to work before the introduction of the unit package.

In other areas Maples unit conversion functionalities are more advanced.

Plotting with units for example has been improved to the point where unit conversion errors of quantity expressions are almost impossible (in contrast to numerical-value expressions): The user can specify the units to display and the numerical values of the physical quantities are converted accordingly.

S1: To catch up with that improvement, conversion of the results as in Example 1 in the form of quantity equations would be desirable as well.

Other desirable unit conversions of quantity expressions are

For all suggestions, it is important that the physical quantity to be converted does not change, i.e. if a unit is changed, the numerical value of the physical quantity is changed accordingly.