I'm not a lawyer, and my knowledge on patents is limited. I guess RSK WILL endorse DPL or will make the required actions to make sure the things developed by RSK remain free and open. This was not a priority until now, but coding was. For me, coding always is the priority.
I will discuss prioritizing this with the team. Remember it took several years to BlockStream to decide for DPL and not just publish everything as they were doing. I suppose the decision it was not a simple one, involving lawyers advise and all. I guess DPL needs to actually patent the things in order to open them later, and patenting has a very high cost.
Give us time to decide which open source strategy is the best and cheaper for RSK. At this point I can assert that RSK has not filed any patent not is planing to. This proposal is not encumbered by any patents, and drivechains is actually not RSK's idea, but Paul Sztorc's.