I'm making a low-res-looking game, but running at a higher resolution. This is so that, for example, I can render this:

However, keeping all of the pixelated elements lined up is a total pain; up until now, I've been offsetting the sprites by the rounding error.
Of course, 'viewport' stretch mode is available, but it should be obvious why I don't want to use this here. Here's that same text in-game:

So, I'm now using a scaled-down child viewport (along with a sprite to display its texture) to sort this out. The problem here, though, is that I can't select/move the viewport's child nodes in the visual editor:

Note that although the label is selected, I'm not seeing a box around it on the right.
Is there any way around this?