Answer:
There is no general recommendation for this.
For wall corners and wall ends, you can initially keep the default setting of "Unsmoothed shear force over the critical perimeter".
After the calculation, you can graphically check the distribution of the shear force in the control perimeter.
Optionally, you can switch to "smoothed" (for example, when singularities occur).
Please note, however, that any singularities that may occur are also included in the beta calculation. If necessary, it may then also be necessary to specify the load increasing factor ß directly by the user.