Something that I do to most of my nylon wing bolts may be of value to you. I use a kids hand held pencil sharpener to taper the first 2 or 4 threads on the bottom of the bolt to create "starter threads". With the high angle of the front bolts in relation to the plate in the top of the fuselage some starter threads might help get the "screwing" started. Of course make sure you have enough length. This helps even on bolts not having an angled start.