Tilting the tool in any direction may result in plastic vanes falling out. This can turn into quite a mess if they already have glue applied. Speaking of glue, if you have ever fletched an arrow you will understand that applying just the right amount of glue takes practice. This, of course, has nothing to do with the E-Z Fletch because it is a factor when using any tool. Another item to be mindful of is the quality of fletching being used.
Quality varies with material and manufacturer.
This will have a great affect on the overall quality of your arrow fit and function, not to mention looks. Be sure to check each individual fletch before applying it to the arrow. In a package of over 30 plastic vanes I purchased, five were unacceptable and had to be discarded. After each arrow has been completed, wipe any excess glue from the tool arms using an acetone dampened lint free cloth. When the folks at ARC designed the E-Z Fletch family they incorporated a material for construction that glue will not adhere to.