I echo your concerns about intent versus application. It took seven or eight years before the U.K. version of this law was used to strip all people in the U.K. of a critical encryption safeguard for their Apple iCloud backup. It's not the immediate intent of the government that's relevant. It's how the bill could be applied over time.
In this instance, the bill does prohibit the imposition of systemic vulnerabilities, but that, by definition, does allow non-systemic vulnerabilities, first. Second, it leaves a lot of e-terms in the definition open to interpretation through regulation.
A big problem with the constant attempt to maintain end-to-end encryption secure is the multiple ways that governments and bad actors keep coming up with to get around encryption. Some of these mechanisms directly compromise encryption. I've seen government definitions of back doors limited to those examples, but other tools that are commonly advanced, for example, client-side scanning, which essentially places an AI tool on everybody's device that monitors their content before it's encrypted and sent onwards and has been assessed by leading security technologists around the world as creating systemic vulnerabilities, do not compromise encryption in the way that this exception would prevent. You need a comprehensive exception that rules out all back doors and all ways of bypassing encryption.
Thank you. I'm sorry for the long answer.