No, I don't believe there is a way to modify this behavior.
On the K-3 (and my K10D before it, IIRC) the pattern is that the last set values are the basis for the next settings when switching between Tv, Av, TAv, and M modes. Sv and P modes are outside this rule. In other words, the settings that don't vary are remembered. The wild card is manually set ISO. It remains the same except for TAv and Sv modes. In the latter case it is always the last set value for that mode.
Example:
- Aperture set to f/8 in Av mode
- Switch to TAv and it is still f/8
- Shutter set to 1/500s in TAv mode
- Switch to M mode and shutter is still 1/500 and aperture is still f/8
- Switch to Tv mode and the shutter is still 1/500 with aperture floating to f/2.8 to make the appropriate exposure
- Take a shot
- Switch to Av mode and aperture is still at f/8
I don't know how this differs from Canon, but I believe that the behavior is consistent for Pentax and is valid/logical.
Steve