Right now, we can not know that the TC requires proxy/VPN before we accept and Test Cycle starts. I sometimes can not reach any wifi and have to test with cellular data. Because I do not know the requirement before accepting the TC, I can not be beneficial in such Test Cycles. I have to wait till reaching a Wi-fi. This situation is "similar for VPN" also. Testers may prefer test cycles without VPN because of technical difficulties or personal prefers.

It is better to provide the requirement about Proxy and VPN before accepting the TC (maybe with the email invitation) so that the testers know these requirements before accepting them.