The attribute tells web developers how much improvement the DelegatedInkTrails API will provide to their current ink latency. However, this attribute is not worth increases to fingerprinting entropy.
expectedImprovement tells web developers how much improvement the DelegatedInkTrails API will provide to their current ink latency. However, this attribute is not worth increases to fingerprinting entropy. The difference in cost to the web developer between using the expectedImprovement attribute and actually delegating the "wet" ink trail to the OS/Browser is minimal, and upon additional discussion, there was no good reason found for the web developer not delegating the ink trail after receiving some value from the expectedImprovement attribute (all improvement is good improvement). The removal of this attribute should have minimal impact to web compatibility as it was never implemented in Blink in the first place. This is the intent to remove the attribute from the web exposed DelegatedInkTrailPresenter interface. There is no usage of this attribute according to blink use counters.