LOL, you recommended doing so in your original post. I suppose that was first impressions before starting to use it.
You are correct - I was initially concerned that the pins could/would walk out of their holes on their own accord under recoil, or what have you. That would leave you with a non-functional rifle in the field, which is generally unacceptable. However, with a bit of experience with the Takedown Pins I can safely state that the design is sufficiently robust with the Retention Springs that the Pins cannot walk out. They have to be deliberately removed, making their accidental loss in the field a consequence of human error, vice mechanical or design failure.
I honestly don't think that there is an absolute "correct answer" to the question of critical spare parts carriage afield. In my opinion, it is a personal choice and in some cases may be context-driven. A SHTF/TEOWAKI/NRL situation is going to have different requirements than a typical, relaxed day at the rifle range, right? In the first instance, you definitely want to carry critical spare parts such as a spare Bolt (complete), Firing Pin, Firing Pin Retention Pin, and specific to the Raven, one (or 2) of the removable Takedown Pins. In the second situation you may have those parts on-hand in your Range Bag, or not. Either way, the success of your Range trip probably doesn't hinge on having those spares and even if it does, it is not a matter of life and death.
Whether or not you choose to carry a spare Takedown Pin (or Pins) during your recreational use of the Raven is entirely up to you. Nobody is going to suffer or die if you lose a Pin without a spare, so who really cares? If you have storage in your Pistol Grip or Buttstock, why not carry a spare? Better safe than sorry. Even better yet, modify your stock to securely hold the pins in holes during disassembly so that they cannot get lost (like an HK G3). There is more than one way to address the spare Takedown Pin storage/carriage issue if you think about it.
At the end of the day, we are expending far too many brain cells and bandwidth discussing this particular issue! Unless it is a life or death situation? It doesn't really matter if you choose to carry a spare Takedown Pin or not, however if you have the ability to carry a spare somewere on/in the rifle, then why not?
B5 SOPMOD Stock modified to retain 2 x Raven (Extended) Takedown Pins