I need to create an unorthodox staircase that consists of multiple treads with unique properties. Is there a way to accomplish this?

A staircase consisting of custom stair treads can easily be created using multiple landing objects, all of which can be placed using the Landing tool. Although the Landing tool is typically thought of when creating a platform between multiple stair sections or to another floor platform, its versatility allows it to be used to create individual stair treads.
One benefit of using landings is that they will recognize stairs, as well as other individually placed landings, and will automatically adjust their height when connected to these like components. Additionally, you're also able to disable this automatic functionality and input your needed specifications for finer control, which is the method we'll be covering in this article.
Another benefit is that landings can be customized using the polyline edit tools to be any shape you desire, giving you the ability to create a fully custom staircase consisting of different sized treads.
In this example, we will be creating custom starter treads, each at a different size, which can only be accomplished using the Landing tool.

Note: A free-standing interior landing will have a default Top Height equal to one riser plus the thickness of the default floor finish. A free-standing exterior landing will have a default top height equal to its thickness. When this box is checked, the landing height may adjust as needed to maintain consistent riser height in all connected stair sections, ramp sections, or adjacent landings.
If snapping the edges of your landings together you can keep the Auto Adjust Height box selected, as it will automatically raise your landings to create steps. In this example we will not be snapping the landings together, so we will turn off the automatic functionality.
Note: A free-standing landing will have a default thickness of 6 3/4” (169 mm). When checked, the thickness is based on the riser height of the stair sections it is attached to, or the thickness of the ramps it is attached to.

You can find more information about these tools by referencing the program's Help documentation.

Note: If you're not creating custom treads that have curved/filleted/chamfererd edges it will be easier to use the Copy/Paste tool to create your copies. This Transform/Replicate method discussed here is quite useful for when you have curved treads, as it will keep the curve consistent across different sizes.

You can find more information about these options by referencing the program's Help documentation.

When using Temporary Dimensions to adjust the new tread, you can select the Move Object behavior to move the object instead of resizing it. This will be useful for repositioning your custom treads that have curved edges.

For more information on drawing railings that follow your stairs/landings please see the Related Articles section.