Im an advocate for multipurpose tools. Clipping the head off with a pair of dikes is just fine. Actually, never had an issue cutting an existing zippy with just a pair of dikes. We all have dikes. No special tool needed. Is this really an issue for some? Cutting zippys?

Knife? No way.

Velcro, all the way.

SnapOn makes an awesome pair of flush cut dykes. On my 3rd or 4th pair from over the years. Was introduced to them in my car audio days.
They are so sharp and cut so flush, I can actually use them to trim hangnails...
The right tool for the job is the only way to go!

Absolutely - way easier to cut off.

I have to agree on all accounts. Plus once you have the feel for a good pair of dikes, you can use them for stripping wire (stranded only), pulling nails, cutting screws to length, the options are endless.

This. I have my Klein stainless snips that I use for everything. Place the blade at a 90* angle the the tywrap and it will slide across the latch, slicing the excess clean off.