suggestions for a tiny speaker with specific requirements

[meeotch]

I need several small powered speakers for a sculpture project, but the nature of the project implies specific requirements. The speakers will be installed on a flat board hanging on a wall, and covered by a mask that has low clearance.

1. no bluetooth needed - wired AUX input mandatory. Ideally, the wired input would disable the bluetooth altogether, as well as any auto-off feature.
2. if the batteries die, and power is subsequently restored via cable, the speaker needs to return to the previous settings (power on, volume setting as before).
3. if there's an auto-shutoff feature, it should be disabled by having the AUX wired input connected.
4. small form factor: I'm currently looking at the Tribit Xsound Go, which is 6.7 x 2.4 x 2.2 inches - but a "flatter" (less deep) form factor is better.
5. ideally, the AUX input would be on the side, rather than the back, or at least flush with the surface, so that the wires don't have to run out the back of the project, which will be wall-hung.

#1-3 are mandatory, #4 is important, #5 is important, but I could work around it with a sufficiently flat speaker.
So far, only the smaller Tribit and Oontz models have hit most of the above. I could go with a bare "standard" driver, and a T-amp, but I'd prefer having it all in one package to save space, and get bigger sound.