Active load cases management during shape optimization is technically pretty much the same as during topology optimization. So, everything from the impact factor to load cases management, as described for topology optimization, applies also for shape optimization.
There are, however, a few issues that are worth being addressed in order to maximize the efficiency of the shape optimizer.
Under certain circumstances, for example to make a quick surface improvement, it might be desired to run the geometry-based steps only while neglecting the stress-based steps within optimization cycles. While this can be achieved by favoring exclusively the geometry-based step, this action alone does not prevent the computation of all active load cases.
This scenario can be made computationally much more efficient and faster if the actual FEA response is not needed in every cycle. This can be achieved by suppressing all load cases, causing effectively that all FEA computations are dropped. This will automatically cause the shape optimizer to run geometry-based steps only, which will make the optimization cycles very fast. Note, however, that in these cycles the actual FEA response such as displacements, stresses, etc., will not be available.
NOTE. All load cases can be suppressed at any stage of the optimization process. This will cause the shape optimizer to perform within each cycle the geometry-based step only.
Eigenfrequency FEA results do not influence the shape optimization process in any way. Thus, the corresponding load cases should be left active (not suppressed) only if the user wants to monitor the lowest eigenfrequency value during the optimization process. If this is not needed, the eigenfrequency FEA load cases should be suppressed to make the optimization faster.
NOTE. During shape optimization suppress all load cases that are not absolutely needed. Any load case can be activated again at any stage of the optimization process.