I use BLEclient to print to BLEprinter. It works well, but ...
My application without BT stack, heap_free = 0x24000
If I compile with BTstack, it gives heap_free = 0x12000
After running BLEclient, connect and print, it gives heap_free = 0x9000

That means push, the system takes about 100kByte ...

I apologize for English. Google Translate
I had the following problem with I2C.
On my board I have the connector I2C, SPI, and IO.
When I plugged a cable ribbon on this connector, I2C completely dropped off, and
I had to be RESET.
If I plug the connector into individual cables, the I2C works properly.

WL_Flash.cpp
esp_err_t WL_Flash::read(size_t src_addr, void *dest, size_t size)
Is this error?
453 result = this->flash_drv->read(this->cfg.start_addr + virt_addr, &((uint8_t *)dest)[i * this->cfg.page_size], size);
I think of this
453 result = this->flash_drv->read(this->cfg.start_addr + virt_addr ...