Both use electrolysis of one type or another in their process as...

Both use electrolysis of one type or another in their process as you've stated so here's some points on that :

A) Electralith state that a very large solar array is needed to power the process as an alternative to baseload supply as a cost saving measure with out this cost saving the process is uneconomical . I put it to you when applied to MANs claims how and where would this happen ?
Electroflow don't state renewables so one has to assume baseload power is required but they conveniently give no hint on economics either the processes are not dissimilar so again how and where ?

B) Electrolysis is not lithium selective so the membrane would act like a sieve IMO in the brine soup where there would be an anode and a cathode where +ve and -ve charged elements would move to either the anode or cathode and the membrane.
In a lab environment the unwanted elements can be dealt with easily because of small scale but when it's applied at commercial scale to MANs Paradox brines which I might add could historically have upto 40% total dissolved solids this is the possible outcome , for every 1 Mt of elemental lithium you extract @ 140ppm or 0.014% TDS you also extract 2,857.14 Mt 40% TDS of unwanted waste elements clinging charged to either an anode cathode or membrane .
Sure you could reverse the Electrolysis process but then you would get the opposite effect what you wouldn't get is your original suspension of individual elements as TDS .
This allies to both companies.

Safe to I'm not convinced and plenty more work is needed to change my mind .

Hope this helps you

Warmest Regards TT