I outlined in a different conversation in this thread that I can see why you have to resort to this: Reddit is not incentivized to ban IPs, and I assume you are likewise not empowered to.
Reddit needs as many eyeballs as they can get, and that is why if you simply ban an account they are able to create a new one; the problem for you, the cog, is unfortunate, but from their perspective they get a new user on their balance sheet every time.
Reddit is incentivized to make your task a struggle that never ends. So it's not that I judge you for it, I judge Reddit's conflict of interest and complete unsuitability as a public square.
That said, I still see what you do as fundamentally cowardly.
Edit: It is intended to be a process with no appeal as a feature. Would you sign up to have your relationship with a community forum severed, secretly and capriciously, and with no appeal or review intended to be possible, at the whim of someone you have never met? And even if you had an attack of integrity, it will never not be a Reddit feature for the reasons outlined above, so your only course of action would not be to stop shadowbanning, but rather, to simply leave the forum for a better one. If Reddit survives as a place where Geographical locations keep their community forums, that will be a horrible fate for us.
If the user doesn't post, then shadow banning is much harder to detect. I regularly see comments from users who were shadow-banned by Reddit; it can take months for them to figure it out. We use shadow-banning only on spammers and trolls. Our process requires peer approval and evidence; there's also an audit trail. We used to ban these accounts, but shadow-banning them instead substantially reduced the amount of harassment we receive. Conflict is inevitable when moderating a subreddit, and we'd rather spend our effort on users who participate in good faith.