Yes, I was aware of this, so I think it would be a fairly easy update. I was specifically referring to the Evernote import though, as strikethrough doesn't come across.
I assume it would be the same handling as for bold ie replace <s> with ~~, but that may be naive.
I planned to do that and checked out the repo. Unfortunately the current dev branch didn't build (as per the build instructions in the README) on my Ubuntu 18.04
npm install
> joplin@1.0.0 postinstall /home/ianjs/dev/joplin
> cd Tools && npm i && cd .. && cd ReactNativeClient && npm i && cd .. && cd ElectronClient && npm i && cd .. && cd CliClient && npm i && cd .. && gulp build
npm ERR! Linux 5.4.0-48-generic
npm ERR! argv "/usr/bin/node" "/usr/bin/npm" "i"
npm ERR! node v8.10.0
npm ERR! npm v3.5.2
npm ERR! code EMISSINGARG
npm ERR! typeerror Error: Missing required argument #1
npm ERR! typeerror at andLogAndFinish (/usr/share/npm/lib/fetch-package-metadata.js:31:3)
npm ERR! typeerror at fetchPackageMetadata (/usr/share/npm/lib/fetch-package-metadata.js:51:22)
npm ERR! typeerror at resolveWithNewModule (/usr/share/npm/lib/install/deps.js:456:12)
npm ERR! typeerror at /usr/share/npm/lib/install/deps.js:457:7
npm ERR! typeerror at /usr/share/npm/node_modules/iferr/index.js:13:50
npm ERR! typeerror at /usr/share/npm/lib/fetch-package-metadata.js:37:12
npm ERR! typeerror at addRequestedAndFinish (/usr/share/npm/lib/fetch-package-metadata.js:82:5)
npm ERR! typeerror at returnAndAddMetadata (/usr/share/npm/lib/fetch-package-metadata.js:117:7)
npm ERR! typeerror at pickVersionFromRegistryDocument (/usr/share/npm/lib/fetch-package-metadata.js:134:20)
npm ERR! typeerror at /usr/share/npm/node_modules/iferr/index.js:13:50
npm ERR! typeerror This is an error with npm itself. Please report this error at:
npm ERR! typeerror <http://github.com/npm/npm/issues>
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
WARN engine sharp@0.25.4: wanted: {"node":">=10"} (current: {"node":"8.10.0","npm":"3.5.2"})
npm WARN deprecated momentjs@2.0.0: WARNING: The correct package name for Moment.js is 'moment', not 'momentjs'.
npm ERR! Please include the following file with any support request:
npm ERR! /home/ianjs/dev/joplin/Tools/npm-debug.log
Ok, that worked fine so I was able to fire up a test instance.
I have submitted a trivial PR to insert the right tags as a starting point. This works fine for for importing strike tags, but still has the limitations of other tags where edge case don't quite work right.