Feature request: Button in My filters tab to display duplicate filters

[xypha]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• using a new, unmodified browser profile.

Description

In Filter lists tab, the following information is seen -

4,65,975 network filters ＋ 3,36,840 cosmetic filters
My filters 3,915 used out of 3,964

This probably means that about 49 filters in My filters are erroneous or duplicate or otherwise unusable.

Feature request:
A button in My filters tab in Dashboard to only display erroneous/duplicate/unused filters (maybe next to the Export button?) so that they can be checked for errors (if any) or cleaned up.
Not sure if this applies to My rules tab too, but if it does, a similar new button would be helpful during cleanup.

A specific URL where the issue occurs.

https://example.com/

Steps to Reproduce

1. Subscribe to multiple filter lists in Filter lists tab
2. accumulate custom filters in My filters tab over the last 5 years or so
3. realise that more than half a million filters is maybe too many and a cleanup/re-assessment of filter lists is needed.
4. first entry in Filter lists tab shows that My filters list has unused filters. A manual check of nearly 4k custom filters against multiple filter lists using asset viewer or More trouble-shooting information is not practical

Expected behavior

Option A -
In My filters tab in Dashboard,

• clicking on Toggle Unused Filters button once, filters out all erroneous or duplicate or otherwise unusable filters for further editing/cleanup.
• perform manual edit/cleanup. Activates the Apply changes button.
• clicking on Toggle Unused Filters button again, removes the filtering to display all filters.

(or)

Option B -
In My filters tab in Dashboard,

• clicking on Unused Filters button open a new tab/pop-up (similar to Asset Viewer), that shows all erroneous or duplicate or otherwise unusable filters.
• perform manual edit/cleanup in text editor after copy-paste.
• perform find-replace in My filters tab and click Apply changes to save changes.

Actual behavior

Button doesn't exist

Configuration

uBlock Origin: 1.61.2
Firefox: 133
filterset (summary):
 network: 465419
 cosmetic: 336872
 scriptlet: 55771
 html: 2497
listset (total-discarded, last-updated):
 added:
  https://fanboy.co.nz/fanboy-antifonts.txt: 58-0, 1d.2h.36m
  https://gitflic.ru/project/magnolia1234/bypass-paywalls-clean-filters/blob/raw?file=bpc-paywall-filter.txt: 1046-2, 42m
  https://malware-filter.gitlab.io/malware-filter/urlhaus-filter.txt: 90396-0, 42m
  https://malware-filter.gitlab.io/pup-filter/pup-filter.txt: 189-0, 41m
  https://paulgb.github.io/BarbBlock/blacklists/adblock-plus.txt: 550-6, 41m
  https://raw.githubusercontent.com/DandelionSprout/adfilt/master/AnnoyancesList: 97148-85, 42m
  https://raw.githubusercontent.com/DandelionSprout/adfilt/master/ClearURLs for uBo/clear_urls_uboified.txt: 760-82, 42m
  https://raw.githubusercontent.com/DandelionSprout/adfilt/master/LegitimateURLShortener.txt: 2699-2699, 42m
  https://raw.githubusercontent.com/Manu1400/i-don-t-care-about-gotoup-btns/master/list-gotoup-btns.txt: 51-0, 41m
  https://raw.githubusercontent.com/Spam404/lists/master/adblock-list.txt: 7252-0, 41m
  https://raw.githubusercontent.com/hoshsadiq/adblock-nocoin-list/master/nocoin.txt: 484-0, 10h.12m
  https://raw.githubusercontent.com/ryanbr/fanboy-adblock/master/fake-news.txt: 584-5, 1d.2h.36m
  [26 lists not shown]: [too many]
 default:
  user-filters: 3965-0, never
  ublock-filters: 41250-157, 42m Δ
  ublock-badware: 12362-388, 42m Δ
  ublock-privacy: 1621-79, 42m Δ
  ublock-unbreak: 2599-2, 42m Δ
  ublock-quick-fixes: 223-6, 42m Δ
  easylist: 78080-2479, 42m Δ
  easyprivacy: 53303-30443, 42m Δ
  urlhaus-1: 23240-9930, 42m
  plowe-0: 3537-1628, 9d.18h.34m
filterset (user): [array of 3965 redacted]
trustedset:
 added: [array of 11 redacted]
 removed:
  chrome-extension-scheme
switchRuleset:
 added: [array of 69 redacted]
 removed:
  no-large-media: behind-the-scene false
hostRuleset:
 added: [array of 1625 redacted]
 removed:
  behind-the-scene * 1p-script noop
  behind-the-scene * 3p-script noop
  behind-the-scene * 3p-frame noop
urlRuleset:
 added: [array of 2 redacted]
userSettings:
 advancedUserEnabled: true
 contextMenuEnabled: false
 largeMediaSize: 250
 showIconBadge: false
 tooltipsDisabled: true
 webrtcIPAddressHidden: true
hiddenSettings:
 autoCommentFilterTemplate: none
 loggerPopupType: normal
 popupFontSize: 9px
supportStats:
 allReadyAfter: 3638 ms (selfie)
 maxAssetCacheWait: 1544 ms
 cacheBackend: indexedDB

[krystian3w]

What annoys me is that I already have about 100 lines (out of 50 filters) in my filters.

Tests:
https://abpvn.com/ruleChecker/redundantRuleChecker.html
https://www.certyficate.it/redundant_checker/redundantRuleChecker.html
https://adblockplus.org/redundancy_check

[gwarser]

Duplicate? gorhill/uBlock#2364

[freezer2022]

Yes, also: gorhill/uBlock#3054

(there is also another one, but only semi-related: #519)

[gorhill]

This can be a separate tool created by whoever is itching to have this, and could be shared as an online tool and available to all -- not just uBO users, -- it doesn't have to be in uBO.