NimBLE: impossible to set MTU more then 256 bytes?

[newsettler_AI]

Hello, I'm trying to set MTU as max as possible (or at least 500 bytes) with android app nRF Connect:

nrfconnect.jpg (29.75 KiB) Viewed 1864 times

But seems in NimBLE max mtu limitted to 256.

Tested in default examlpe bluetooth/nimble/blehr:

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I (35182) NimBLE: mtu update event; conn_handle=0 mtu=256

And in bluetooth/bluedroid/ble/gatt_server example this is possible:

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I (30086) GATTS_DEMO: ESP_GATTS_MTU_EVT, MTU 500

Does this is internal limitation of NimBLE stack and need use Bluedroid instead if I need large MTU?