This isn’t exactly what you are asking, but related: there is a recently added experiment to show a “New record” button at the bottom of the active view, which you can enable by adding ?experiment=newRecordButton to the URL of your document.
It doesn’t open a card, so you still need to hit Space to get there. But the reason it’s an experiment is to collect feedback. You can add your feedback as comments here: "Add new record" button · Issue #366 · gristlabs/grist-core · GitHub.