Yes, the config can be set via API.
For the Opener we have a new dedicated BLE API document.
Here it can be done with the Advanced Config command, see https://developer.nuki.io/page/nuki-opener-api-110/7#heading--set-advance-config
With the Web API this is a
POST /smartlock/{smartlockId}/advanced/openerconfig
On the Swagger instance change the view from “Example Value” to “Model” to get a description for all settable options.
It is recommended to retrieve the current state of the advanced opener settings via
GET /smartlock
first and then send the whole object with the changed values via POST.