As I run several Puppies and prefer the consistency across operating systems which portable applications enables, I've sort of 'Mikewalsh portablized' Mercury Browser
There were 4 debs available which might be usable on my 12+Year old desktop, https://github.com/Alex313031/Mercury/releases. The avx2 version didn't run: notice of an illegal instruction @ line 69, which may mean my computer doesn't provide the necessary instruction set. The AVX, SSE3 & SSE4 version all ran. My assumption is that AVX includes SSE4, so I chose to work with it. Please correct my assumption if false. You will have to test to determine which version works best with your computer.
Portablizing was fairly straight-forward. I extracted the deb and within found a "usr" folder. Within that were bin, lib and share folders. The bin folder only held a bash-script which is a wrapper; more about which below. The share folder contained the usual stuff. I didn't use any. The lib folder is the 'meat & potatoes' of mercury.
To portablize: create a folder named, for example, mercury_browser-portable.
Copy the aforementioned 'usr' folder into 'mercury_browser- portable. RENAME IT 'mercury' --without the quotes.
From /usr/bin I copied the 'mercury-browser' script into the mercury_browser-portable folder; then renamed it 'LAUNCH'. I edited its concluding section --the part below #Launch executable-- so that profiles would be written to the portable folder. [Thanks, Mike 
].
Although it was not required by F96 on my desktop some new Puppies may depend on Pulse-Audio. I flinched the relevant pulse-lib folder from Mikewalsh's firefox-portable and dropped it into the mercury_browser-portable/mercury folder. The #Launch executable section of the LAUNCH Script was modified with 'if...then' to test and use which --alsa/pulse-audio-- was present. [I flinched the 'if...then' from Mikewalsh's firefox-portable. Thanks, again, Mike 
]. Tested under both F96 and Bookworm64. [Not sure if inclusion of the pulse-lib folder is necessary. But it's small and believe 'having it and not needing it is better than needing it and not having it.']
The attached package contains a DATA folder, LAUNCH, Menu-Add & Menu-Remove scripts, and a folder named pulse-lib. Extract the tar.gz and drop all except the pulse-lib folder into the top of your mercury_browser-portable folder. The pulse-lib folder goes into the mercury_browser-portable/mercury folder if you need it.
