This discussion provided some additional information.
Operated by a South African, who spent under one month from ideation to launch.
The LN Nodes (Core Lightning) run on Raspberry Pi
Due to load shedding by the power utility, but on a schedule, an nginx reverse proxy is used to ensure traffic goes to a node that is expected to have power
The Machankura service charges a 1% fee on transfers (out ?) to cover USSD fees they pay, hopes to reduce that in the future.
USSD sessions have a 20 second timeout, so commands must be sent promptly. [I'm curious ... how could I type a Lightning Address on a feature phone in 20 seconds?]
Wanted to have support for an additional country (Zimbabwe) but the USSD service provider used, Africa's Talking, does not have USSD support in Zimbabwe.
Work had already been underway by a separate group on an open source SMS based LN-enabled (?) bitcoin wallet (bittext). Machankura is supportive of that as well, since it will provide coverage where USSD may not be either available or allowed.
As a custodial wallet, there may be VASP (virtual asset service provider) regulations in certain countries (e.g., Namibia).
Researching innovations (e.g., Blockstreams's GreenLight) to make non-custodial work as well.
There was discussion about running LN nodes -- I wasn't paying close attention. Not sure if they were asking about opening a channel to provide liquidity, or what.
Support for forgotten PIN does not yet exist, will cause user to lose any balance. Not sure yet if that will be added.
When a user loses SIM, they can get a replacement (provisioned with same mobile number) and as long as they know the PIN they don't lose anything.
If lost SIM and cannot replace (e.g., for reasons), user loses any balance.
No insurance on BTC balance. [Something to the effect of best effort to protect funds or something to that effect, I'm not sure what was said.]
This discussion provided some additional information.