Here's a modification I did to a speedy stitcher. The first photo shows one as it comes from the store. I cut the handle short and added three more holes under the collet (chuck lock) into the ferrule to hold 5 needles. Being shorter makes it easier to use as it fits in my hand better and it takes up a lot less room in my sewing kit.
Here's the collet (chuck lock) on the left and you can see the top of the ferrule and the extra holes I made for more needles. I used an automatic center punch to mark the holes and then very carefully drilled deep enough to match the depth of the existing needle holes.
I've edited this post with a copy of the instructions that come with the speedy stitcher.