Replacing a formulae with another?

[MagicalDrizzle]

Output of brew config

HOMEBREW_VERSION: 5.0.4-58-g43d6c11
ORIGIN: https://github.com/Homebrew/brew
HEAD: 43d6c11bfc3bdedfc0a6e02b59114e780aaea212
Last commit: 18 hours ago
Branch: main
Core tap HEAD: 93448d6ae81277a158d0d8b449eb8803efab48a0
Core tap last commit: 4 hours ago
Core tap JSON: 07 Dec 12:36 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: :0
HOMEBREW_DOWNLOAD_CONCURRENCY: 8
HOMEBREW_EDITOR: /usr/bin/nano
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 4
HOMEBREW_NO_ANALYTICS: set
HOMEBREW_SORBET_RUNTIME: set
SUDO_ASKPASS: /usr/bin/ksshaskpass
Homebrew Ruby: 3.4.7 => /var/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/3.4.7/bin/ruby
CPU: quad-core 64-bit skylake
Clang: 21.1.7
Git: 2.52.0 => /home/linuxbrew/.linuxbrew/bin/git
Curl: 8.15.0 => /bin/curl
Kernel: Linux 6.17.7-ba14.fc43.x86_64 x86_64 GNU/Linux
OS: Bazzite (Kinoite)
Host glibc: 2.42
Host libstdc++: 6.0.34
/usr/bin/gcc: 15.2.1
/usr/bin/ruby: N/A
glibc: N/A
gcc@12: N/A
gcc: 15.2.0
xorg: N/A

Output of brew doctor

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Description of issue

I'd like to ask how you can "replace" a formula with another. I installed formulas which depends on ffmpeg, however I wish for them to use my own installed ffmpeg in my personal tap instead, leaving the original ffmpeg formulae not installed. Is there a way to do this?

[SMillerDev]

No, this is not possible. Any formula declares its own dependencies. The only way to change those is to create a copy of the formula and change the dependency. Otherwise there would be no way to be sure the software works.