Thought so. Code is updated, please try again.

Do I hear someone being motivated to make a pull request?

It should work very well for this task. You can find code on Github or via Hackaday projects, the ESP32 has two full-duplex I2S ports which you can use. If I were you I'd just go search Aliexpress for I2S boards that suit you, there are plenty on sale for little money.

And thus the C++ learning curve strikes again:

Nice, looks like you know what you're doing. Can you tell me what hardware are you using? So I can order the parts to test it on my side.

The right abstraction would be a separate URL handler for sd cards I guess. So depending on the URL scheme, the handler would choose http/https/scdard/filesystem or whatever. Not sure how well sdcard access can be abstracted, never done it.

I simply didn't test APLL + PDM, assuming it would work the same as I2S. Can you open an issue on Github please?

There is an A2DP sink example in the SDK, and a working bluetooth speaker mode in here: https://github.com/MrBuddyCasino/ESP32_MP3_Decoder

Its not very difficult, but be prepared to say goodbye to 64k of RAM for BT classic..

I see, yeah I'll figure it out. Sorry for bombarding you with questions. ^_^

Good to know, thanks. Do you know if there is a way to daisy-chain 2 panels, so the aspect ratio is closer to widescreen?