Currently, the font choices in Textastic for iOS are hard-coded in the app. I'll consider custom fonts for a future update.

I've just sent you a TestFlight invitation for the current beta version of Textastic 6 which should fix this issue. You can install it in parallel to Textastic 5 and access your files.

Emmet support is already in the current beta version and will be added in Textastic 6.3.

This is a problem when opening files from Google Drive using the "Open…" command in Textastic. This invokes the iOS document picker and uses the Google Drive file provider extension of the Google Drive app. Unfortunately, the Google Drive app has some bugs regarding handling of file extension that it doesn't know.

Instead, please use the remote transfer screen: tap on the "globe" button in Textastic and create a new Google Drive connection. You can then download and upload files using this connection. It also allows you to download whole directory trees.

Try to use replace instead of append. You can find an example at https://github.com/blach/Textastic-Customization/blob/da5b6db31f84d836519fef2ef60e513e724a0685/CodeCompletion/js.json#L14

{ "string": "forin", "replace": "for (${1:variable} in ${2:object}) {\n\t$0\n}" },

Textastic does have support for YAML syntax highlighting. You can select the YAML syntax definition in the File Properties popover if it isn't selected automatically.

Not yet, sorry.

It works just the same in Textastic 5.3.1. Textastic 6 is not required.

You should see a folder called "Textastic" in iCloud Drive on your Mac, on the Web at icloud.com and in the iCloud Drive app on your iOS device. Files in this folder will show up in the "iCloud" location (below "Local Files") in Textastic for iOS. Files you put there will be automatically synced to all your devices that are logged in to the same iCloud Drive account.