Is the Slave latency, Connection interval, Supervision timeout, Transmit window size, number of advertising channels configurable?
Firmware may be developed for the nRF52 on the module with any of the tools from Nordic.
With your own firmware, Slave Latency, Connection Interval, and Supervisory Timeout can be integrated. Keep in mind that these are negotiated parameters. While the peripheral can request them, it's ultimately the central that accepts or rejects them. Steps and sizes are noted in the attached app note, plus the Bluetooth Core Specification. The Nordic SDK is also another resource for the various APIs to configure these parameters.