Yes, I just checked and I ordered the P-25F. This is good news that it is high quality, has the sound holes on the back, and is capable of bending notes. Your review convinced me I should try it.
You have had these Yamaha’s apart. Are the holes on the back the sole source for emitting the sound?
Instead of putting tape over the holes, try holding the pianica against your chest and stomach while wearing a heavy shirt or two. I think this will absorb the sound and really change its character.