My apologies for the links of TX, i was not aware, but just to be consistent why in the switch homebrew bounty the old link was present in your 1st pages :-) if is forbidden?
This is a good new for the 3DS for me, as i'm pretty sure that nintendo has not put a real focus on the DS mode security.
Let's imagine that has been done intentionally to insure that all owner of the DS will buy the 3ds without thinking about the fact they could lost the previous DS soft.
A...
firmware exploits it's the best solution, just wait the first Lego game.... But i things this will solve "only" the 3ds hardware limitation . For the DS and DSI mode flash card should be the best solution.
A good step to keep the homebrew facilities on the 3ds. We know that is only for DS or possibly for dsi soft in the futur. But is not the open door for the 3ds flashcard.