SilverLite FS-i6 firmware is a firmware replacement for the FlySky-i6 transmitter (and not the FlySky FS-i6S or the FlySky FS-i6X). This custom firmware was designed for my particular use case: controlling 65mm/75mm whoops and micro (100mm) sized quadcopters. The features that are available along with the user interface are therefore rather limited. It does just what I need and not much more.
This firmware is primarily designed to interface with flight controllers running Silverware or variations of that software: BWhoop Silverware, SilF4ware, NFE Silverware, NFE Silverware with SilverLite extensions (a fork I made but haven't released), and SilverLite.
All of these Silveware based flight controllers provide support for a Bayang protocol. This is the protocol that SilverLite FS-i6 is primarily based upon. However this requires a hardware modification to the FlySky-i6 so that an NRF24L01 transceiver module be installed. The internal A7105 transceiver module is left alone and intact, but the firmware simply ignores it.
In addition to the Bayang protocol, SilverFlite FS-i6 can also work with a multiprotocol module connected via serial (trainer port on back of the i6). This restores the FlySky protocol as well as introduces the huge variety of additional protocols provided by Pascal's module.
Documentation for SilverLite FS-i6 firmware can be found here