If everything sounds OK, I wouldn't worry about it.
There is no advantage to use of an analog attenuator. Both analog and digital attenuation reduce the theoretical SNR of the preamp output signal.
That's usually my argument, but...
48dB is 8-bits so with 45dB of digital attenuation and 24-bit audio you still have more than 16-bits.
But with 16-bit audio you are almost down to 8-bits of resolution and you may hear quantization noise. Quantization noise sounds like a "fuzz" on top of the signal and like regular analog noise it's most noticeable with quiet sounds. But unlike analog noise it goes-away completely with digital silence. (You can make an 8-bit file with Audacity. If you try it, turn off Audacity's dither.)
This is not a concern with regular "digital volume control" when you don't have "excess gain" because the quantization noise remains the same low-level (usually inaudible) as you turn-down the volume digitally.
The problem comes when you attenuate and then re-amplify, and your high-gain amp is amplifying any quantization noise.
An analog attenuator at the DAC output will (obviously) attenuate the signal and noise together so the S/N ratio remains the same at that point. Without re-amplification, that lowers the absolute level of any noise making it less audible. The high-gain amp will re-amplify that existing noise and add-generate SOME analog noise of its own, but the noise generated by the amp is unavoidable and will (obviously) still exist with digital or analog attenuation.