How necessary is it to totally restrict readers with suspicious IPs? This feature is for readers, any reader can get so IP. The IP problem will only get worse. Perhaps it will be enough to request a captcha (only for those coming from the sidebar with such IP) or remove this restriction. See also meta:Talk:No open proxies/Unfair blocking, [1][2][3], en:Wikipedia:Blocking IP addresses#Problems and solutions. @OVasileva (WMF), @Ladsgroup, @Krinkle. @Pppery, started a new topic here, as you advised
Topic on Extension talk:UrlShortener
While I understand, the short urls have potential to become abuse vectors, e.g. to be used to disclose someone's identity. That's why it's not allowed to create a short url while blocked. The focus should be to reduce unfair block of IPs tbh.
I’m not sure that this helps in any way specifically for Wikimedia sites, where statistics and data on those who used the link are not provided for users.
I’m not sure that the fight against unfair blocking will lead to anything serious: this problem may not be solved for years, IPs are now being resold very actively. Moreover, since IP masking is planned, the blocking will only get stronger, in my opinion. A separate problem, as far as I understand, is that many people use proxies regularly.
In the abstract, preventing blocked users from performing on-wiki actions is a reasonable anti-abuse measure. I don't think you'd disagree with that?
Anyways, agreed with Ladsgroup here. The problem is that "blocked users" includes a number of people who (presumably) have done nothing wrong and are just being blocked for their IP address, VPN, etc. That is the central issue that needs to be solved and trying to address it feature-by-feature is going to be a mess and endless rehashing of the same discussion. Adding workarounds just reduces the incentive and pressure to solve it properly.
The key difference is that it is a tool for readers.
Readers are generally not restricted no matter what IP they have or whether they use a VPN. Besides, they won't even understand what it is