Does DisplayPort in Librem 5 require a binary firmware?

What I meant is some other way to get video output of USB port with an adapter to retain convergence without DisplayPort.

For example, Purism laptop users reported that it is possible to use older DisplayLink USB 2.0 adapters under PureOS without proprietary drivers or firmware.

ThinkPenguin also sells such an adapter.

Some also proposed to use multiple adapters to get multi-monitor support.