How might I be able to control Bluetooth HCI level commands/events on Android devices?

I'm doing some Bluetooth iop tests for work and need to see if our host code works with an android device's controller.

Specifically, I need to be able to send HCI commands, such as - https://source.android.com/devices/bluetooth/hci_requirements - and change values for certain parameters (via python or shell scripts ideally)

Thus far, I haven't had any luck finding ways to do this online.

I've tried using SL4A to run python scripts that work with HCI, but SL4A uses its bluetooth 'facade' (http://www.mithril.com.au/android/doc/BluetoothFacade.html) to control fairly high level commands.

I've looked into ACTS, CTS, and other similar android suites (https://source.android.com/devices/bluetooth/verifying_debugging) but didn't find anything that could work with HCI for testing purposes.

I looked into bluedroid testing tool (bdt) (https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/jb-mr1-dev/test/bluedroidtest/README.txt) but was unable to build or run it successfully for the device I'm testing against (Pixel 2, which uses fluoride stack).

I've looked at Fluoride Bluetooth testing (https://android.googlesource.com/platform/system/bt/+/master/test/README.md) but again had issues building and running the tests, and I'm not sure that once I get it working it will operate at the level I need (since it's built for testing fluoride, which is host level).

I'm in the process of creating a pixel 2 build from AOSP to see if that will allow me to better utilize some of these tools or access any I haven't come across.

At this point I'm a little clueless and would appreciate any help or guidance that might point me in the right direction.

(Posts I've looked at:

-Bluetooth HCI command for enabling BLE advertising

-Looking for open source Bluetooth Stack (HCI) for STM32F4

-Direct Control of HCI Device (Bypass Bluetooth Drivers) on Linux

-How to enable Ble Advertising using hci tool on android?

-Can I send Bluetooth HCI packet in Android with Java?

-Bluetooth Communication flow in Android)