AxoTools now includes an Axo Shear tool that will allow you to shear artwork that’s already been projected onto an axonometric plane. It functions similar to Adobe’s Shear tool in that its default anchor point is the center of the selection, but you can click to place the anchor anywhere you’d like.
The plugin will display a cube annotation with one of the three axonometric faces highlighted. Simply tap the Alt/Option key to choose the plane you’re working on. Drag to shear the art, and the current shear angle will be shown near the cursor. Press the Shift key while dragging to constrain the shear to increments of 15°.
To shear art numerically on a projected plane, Alt/Option click on a location for the anchor point of the operation. In the dialog box that appears, fill in the shear amount, the axis angle to shear on, and the face upon which to shear.
The new tool is available in the current version of AxoTools for Adobe Illustrator 2019 – 2022. You can download it here for either Mac or Windows.