TrustConnect for Android using L2TP possible?

Could an LT2P connection from Android to TrustConnect servers work?

On a Nexus tablet with Android 4.3, TrustConnect works OK but drops often without any notice and, for what it is worth, also seems to conflict with NoRoot firewall–each stops the other. I have only been able to get it to work configured for PPTP. There is a way in 4.x to only allow internet access over the VPN but it requires L2TP, which is supposedly stronger as well. I have not tried, but if I have it right, OpenVPN clients are supported for Linux. From what I have read only tun is supported on Android, not tap, so I tried a hack by configuring an ovpn profile that way and was able to import it. But OpenVPN on Android does not appear to be satisfied with the Comodo-downloadable ca.crt referred to in the ovpn. Instead you get a pop-up stating that it requires a pfx/p12 file. This even though I was able to import it into the User Credentials under security settings. If this is possible, any useful pointers on generating the pfx/p12 for TrustConnect would be appreciated.