For its unique engine to function, StarTools needs to be able to make mathematical sense of your signal flow. That's why it's simply unable to perform "nonsensical" operations. This is great if you're a beginner and saves you from bad habits or sub-optimal decisions.
Just like in real life, in astrophotographical image processing, some things need to be done in a particular order to get the correct result. Folding, drying then washing your shirt, will achieve a markedly different result to washing, drying and folding it. Similarly, deconvolution will not achieve correct results if it is done after stretching, ditto for light pollution removal and color calibration. In mathematics, this is called the commutative property.
The "Tracking" feature, constantly backward propagates and forward propagates your signal through processing "time" as needed. This means that "nonsensical" signal paths (e.g. signal paths that get sequences wrong) would break Tracking's ability. Therefore, such signal paths are closed off. For this reason, it is neigh-impossible in StarTools to perform catastrophically destructive operations on your data; it simply wouldn't be sound mathematics and the code would break.
The "Tracking" feature, constantly backward propagates and forward propagates your signal through processing "time" as needed.
For example, the notion of processing in the linear domain vs non-linear (stretched) domain is completely abstracted away by the engine because it needs to do that. If you didn't know the difference between those two yet, you can get away with learning about this later. Even without knowing the ins-and-outs of astronomical signal processing, you can still produce great images from the get-go; StarTools takes care of the correct sequence.
So, whereas other software will happily (and incorrectly!) allow you to perform light pollution removal, color calibration or deconvolution after stretching, StarTools will...
...actually also let you do that, but with a twist!
Tracking will rewind and/or fast-forward to the right point in time, so that the signal flow to makes sense and is mathematically consistent. It inserts the operation in the correct order and recalculates what the result would have looked like if your decision had always been the case. It's time travelling for image processing, where you can change the past to affect the present and future.
For an in-depth explanation of Tracking, see the Tracking section.
I'm relatively new to image processing and just wanted to say how straight forward and powerful StarTools is.
Select the 'decode the data from a Base64 string (base64 decoding)' radio button.
You can convert everything you see to a format you find convenient. Give it a try!