Even default Safari Web Extension project is not displayed on iOS 18.4 simulator ("No extensions installed"), so it's not possible to test extensions in simulator, only on real device.

I have a Safari Extension which replaces default new tab and puts a link on a generated new tab. This link can be either usual URL link, or a URL Scheme, something like plecoapi://x-callback-url/df?hw=${char}&sec=dict In iOS 17 and previosly, this link worked flawlessly. In iOS 18, including 18.2, this X-Callback-URL link works only once, if I kill Safari process, reopen Safari and tap the link. Each subsequent tap will just reload the page, link won't work anymore until the next Safari reload. Usual URL links works every time without a problem.