calibre-kobo-driver VS kepubify

The challenge here is that you would have to go through the plugin releases for the KoboTouchExtended plugin and find one that is old enough to still be compatible with your version of Calibre.

OP probably just means stuff like kobopatch [ https://github.com/pgaskin/kobopatch ] or Calibre plug-ins that are handy to work alongside the Kobo, such as this extension to the KoboTouch driver [ https://github.com/jgoguen/calibre-kobo-driver ]. I personally don't use kobopatch, but the extension for Calibre's KoboTouch driver has been v useful for me.

The big utility of WASM for me, like OP hints at, is bringing things that would be infeasible to port to the web to it, like, say https://pgaskin.net/kepubify/ and other conversion tools (eg ffmpeg-wasm). Much preferable to downloading something or uploading a file to some random person’s server

But now just before I did the whole NickelMenu hack I realized that if I download for example 10 epubs and put them on a folder in Dropbox with my phone the kobo will pick them up easily but not perfectly since they will be in epub format and not kepub.... So in the end why risk and spend so much time installing NickelMenu? If in the end probably I will probably still need to go to https://pgaskin.net/kepubify/ to convert my epubs to Kobo Epubs one by one to then put them in Dropbox..

If you don't want to use Calibre at all, you can also convert epub to kepub using https://pgaskin.net/kepubify/ and then sideload the kepub file you get manually on your Kobo

Kobos are good. You can load them with your own files and they support a nice range of formats. Before loading EPUBs, convert them¹ for better performance². Old models keep getting software updates for years, and those can improve performance.

¹ https://pgaskin.net/kepubify/

² Though you don’t have to, unconverted EPUBs load fine.

I use kepubify. It works well for me

Yes, you need to run kepubifiy first https://pgaskin.net/kepubify/ and put in dropbox folder the file you get after conversion :)

Convert them to kepub https://pgaskin.net/kepubify/

Kepubify (pgaskin.net)

Pick whatever file you want and use kepubify to generate the kepub