30 AWG is typically 11 conductor, 0.08mm/conductor, -60 to 200°C, voltage ratings vary depending on who you believe.
Multistranded wicks solder partway up the wire, creating a stress point. And the multiple strands make the wire "elastic." It has a set position where it wants to twist around to. When you bend the wire, it bends back... But every time it gets bent, it gets stressed at the aforementioned junction.
Say the wire gets pushed down. Even though each and every strand is being bent beyond its elastic limit into permanent plastic deformation right at the junction, at the surface of the solder boundary, the wire doesn't lay down. It gets back up, again and again, as the wire relaxes. The tensile and compressive elasticity in individual strands is pulling the wire back up like a puppet by strings, and it unfolds most right at the same weakened point which is acting like a hinge. Each repeat occurrence, this may exceed the elastic limit for the material at this hinge point, depending on how much the wire got disturbed by whatever the means. The rest of the wire is busy sharing and unloading any residual compressive or tensile forces along its entire length... and all of the bad stuff happens at the joint.
Vibration will also cause breakage. For intra-PCB jumpers, solid core is the way to go. You want it to lay where you bend it, to stay out of the way. This alone is a deal breaker.
According to one seller the OD of this 11 stranded 30AWG stuff is 0.8mm. Kynar is 0.5mm. That is around 2.5x the cross section. This alone is a deal breaker.
This stuff is for cable assemblies... using proper strain relieved connectors. You don't want to do any point to point soldering with this stuff. It's also called "tonearm" wire, because apparently it's used in the arm of a record player and other vintage equipment with moving parts (properly strain-relieved, of course).
If you're wiring up a circuit on protoboard, you want solid core wire. Well, in the future you will realize that you do, anyway.* At 30AWG, Kynar insulation shrinking back isn't really an issue the way it starts to be with the larger gauges.
No. Wire wrapping wire is meant for ... wire wrapping and that is why it is more expensive.
It doesn't need to be expensive. It's often sold in smaller quantities for a relatively high price for one-off jobs for people who don't normally do stuff like this. It's also sometimes called "mod wire" or "bodge wire" as it's very commonly used for reworking pcb's with solder, not just for wire wrapping. I probably pay 5-6 cents per foot for the good stuff. It can be had for 1/3rd of that from Hong Kong or China in 1000 foot reels. If I'm gonna use a 1 cm section, I cut off a foot. And throw the rest away. I use it for doing continuity test on pcb points, soldering the wire directly to the board and wrapping the other end to a banana jack with a post on it. And when I'm done I put the banana jack away and throw away the wire. When I use a solderless breadboard, I mostly make connections by putting pin headers in the board and wrapping the jumpers between pins. When I'm done, I put the pin headers away, and I cut up and throw away the wire. 30AWG wrap wire is essentially free, AFAIC. The cost is insignificant.
*And you will end up at kynar wire, unless you are one of the enamel coated wire folks (weirdos).