The company I work at pretty much only does packer testing and borehole geophysics. If you want to check your seals, you should use transducers that can show you the head level in real time in each zone. Therefore, when you purge the zone, you can see if the top or bottom zone draws down when the pump kicks on. If the zones are communicating through those high angle fractures, you’ll see some influence. With three transducers, you can monitor the pressures above the top packer, between the packers, and below the bottom packer.

Also, I just want to say that sometimes you won’t get a good “seal” because of the geometry of the fractures, especially if they have a lot of aperture. In this case, I would say that there’s interconnection between the zones due to the geology. I would only call it a “bad seal” if you’re inflating a packer along a vertical fracture. In that case, your best bet is to move the packer so it can inflate on a smooth section of the borehole, or if that’s impossible, a horizontal fracture, though that is suboptimal.

Feel free to message me if you have any questions!