Just seen this thread and by total coincidence I bought one of these tools a month or so ago, I’ve not used yet so can’t comment on how successful it will be. I’ve used toothpicks in the past but the issue (for me) is getting the right amount of paint on it, it’s usually too much or too little for the chip at hand, and a pain keeping going to the pot for a reload. I think if you are just doing one or two chips then a toothpick may still be the way to go. This tool looks great for an attack on multiple chips.
One thing I worry about with this tool is whether it will work on vertical surfaces or whether the paint will just run out of the reservoir, but it does look to produce very small blobs that should be great for small chips or can build up multiple blobs for bigger chips. As said trying to go with base then lacquer isn’t going to be easy IMO, either just use base or mix a bit of base and lacquer first.