Although cFosSpeed supports task offloading, it depends on a couple of factors:
You can check, if task offloading is enabled by checking the flags for the active adapter in the cFosSpeed settings (Adapter Info): The following flags should be on for IPv4 / IPV6 receive and transmit: tcpchk, udpchk and for IPv4 also ipchk.
For Large Segment Offloading "Offload LSOv2 IPv4" and "Offload LSOv2 IPv6" should have a minsegcnt of 2 or more.
Currently Receive Segment Coalescing is only active in expensive adapters. If enabled, "Offload RSC" should be IPv4=1 and IPv6=1