No, is the answer to the 2 screw suggestion and you need to pre drill the holes. You could use hidden fasteners but that is a lot more work and costs even more than the screws. There must be some reason why you chose this particular timber so if you want to go with it you have to use ss screws. Obviously a stained softwood would be cheaper and you could use ceramic covered deck screws (no pre drilling) but the appearance will suffer, you have to decide how important it is to use ipe.

I just wanted to chime in here on one thing. I don't know about the screws or decking but I have had a lot of experience with ipe wood. We have a very large, custom firepit seating made of ipe and about ten pieces of garden furniture made of ipe. It is as strong and wonderful as they say, but, it silvers (color) more quickly than teak and to keep the beautiful, warm brown color which I love, you need to oil it about three times a year. That is simple and so rewarding. Go for it. Spend the money and have it for many, many years.