The devices supported are quite old. What are the blockers for a recent phone? Are bootloaders not unlockable? Are drivers not available?

Supported Devices:

Devices device: arale: This issue affects the Meizu MX 4.

device: bacon: This issue affects the Oneplus One.

device: cooler: This issue affects the Bq M10 HD tablet

device: deb: This issue affects the Nexus 7 2013 LTE.

device: flo: This issue affects the Nexus 7 2013 Wi-Fi.

device: FP2: This issue affects the Fairphone 2

device: frieza: This issue affects the Bq M10 FHD tablet.

device: hammerhead: This issue affects the Nexus 5.

device: krillin: This issue affects the Bq E4.5.

device: mako: This issue affects the Nexus 4.

device: manta: This issue affects the Nexus 10 tablet

device: turbo: This issue affects the Meizu Pro 5.

device: vegetahd: This issue affects the Bq E5.

device: w7: This issue affects the LG L90.