For anyone interested, here are the working Nowforever D100 VFD (same parameters as E100 FW 1.3) settings for modbus (modbusez plugin UCCNC)
parameter - default -> new
p000 - 1 -> 2
p001 - 0 -> ok
p002 - 2? -> 6
p055 - 1 -> ok
p056 - 2 -> ok
p057 - 0 -> ok
UCCNC settings for actual spindle speed DRO:
UCCNC Sact label setting 870 (default) -> 2451 (new)
The rest is as in the "screen shot" below (select com port from your installation).