If your 3in1 is the newest kind, I don't think those work with the Opera Browser yet.
Otherwise, all you need is the correct patch for the opera browser. There are different patches for different Slot 2 carts, so you need the one for EZ 3-in-1.
Not sure where to find it, download center has the patches for M3/G6/Supercard Slot-2's and EZ4 deluxe, but not EZ3-in-1.
If you have no clue, then i can't even help you because i don't have this flashcart. Search a little with google.
Some fake R4 use the same GUI than DSTT, perhaps you have to click the Plus icon next to the nds you want to disabled softreset.
It is important that you reply with the details of your actions.
Saying it doesnt work doesnt allow anyone in here to backtrack your steps.
That means that if you done something wrong in installing or handling certain files you could never do those steps right , which means that no one would be able to point out what you might have done wrong.
Do you have any other flashcart other than the R4 clone to try it on? There are some of the same complaints in the R4 section about certain clones that got the same problems as you, might be the R4 clone itself.
I can't tell if yours is the same as thiers, some of the complaints are too few in description of the problem and come with the phrase "I can't run opera on my R4". From what I can tell there are about 7 different R4 clones and mabe more, and about 2 of them don't seem to run the opera browser under any condition.
Can we start from the beginning with what R4 clone you got, that way we can help you better.