I was able find two parameters that Edge supports for PDFs: page (on StackOverflow) & view (on GitHub). But I'm wondering whether there are any others? However, searching for them with the query edge pdf url parameters doesn't yield any helpful resources. The only page that looked like that PDF reader in Microsoft Edge doesn't name any parameters.
Do you know whether they belong to some standard that Edge implements and where they could be documented?
Microsoft Edge version 77 or later is based on PDFium/Foxit reader in Chromium's.
This is changing in MS Edge from March 2023 to March 2024 into a currently optional experimental Acrobat Lite often seen in lower right as "Powered by Acrobat". The two MS Edge PDF "engines behave different to the "Traditional" Acrobat activeX in I.E. for which the URL#fragments were originally designed.
From a Windows programmers perspective application "interop" is provided either by DDE (often the core of PDF viewer control) or by other programmatic means such as -switches via command line arguments. Which in this case are translated via URL # fragments. For the old Adobe list see https://pdfobject.com/pdf/pdf_open_parameters_acro8.pdf
Currently Chrome should support a number of those as defined by Adobe. However, that for several reasons, does NOT include "Search"
Over a long period of time the various abilities have been addressed by PDFium/Chromium teams so for example.
Table 151 in ISO 32000-1 standard lists multiple view destination parameters.
Some of these have only recently been "fixed" in Chromium so for example
March 2023 "Add support for FitB* view mode for Chrome PDF viewer"
Fit for release in June 2023 versions, thus may not be in all users Chrome or Edge.
So for any given requirement you need to do your own tests. However beware other users may not have the latest switches included in their viewer.