Yes, you have to complete another 2 years to be able to transfer to another sponsorship.
If you really need to transfer again, have your current visa cancelled, go back to your origin country, have your new company apply new RP for you with the NOC and u can come under the sponsorship of the new company. RP applications are very fast now provided you have all the necessary documents. Sometimes when applied in the morning, in the afternoon it's ok already. So you can come back even the following day.
Yes, you have to complete another 2 years to be able to transfer to another sponsorship.
If you really need to transfer again, have your current visa cancelled, go back to your origin country, have your new company apply new RP for you with the NOC and u can come under the sponsorship of the new company. RP applications are very fast now provided you have all the necessary documents. Sometimes when applied in the morning, in the afternoon it's ok already. So you can come back even the following day.