This is my view also.
In terms of whether IB actually helps with college applications, I am generally of the opinion that high school students should do something relatively close to nothing at all for the purpose of improving their college applications. I think that students need to figure out what is right for them. What level of academic rigor is appropriate for the student? What ECs make sense for the student? So far this approach has worked well for our family.
So, in terms of whether your son does IB or not: What is right for him? The track that includes hands on coding to me sounds like great fun, a good education, and appropriate for someone who wants to go into computer science.
If I were in this situation I might emphasize to my son (I do not actually have a son, but suppose that I did) that keeping up with his sister is a bad idea. Looking for the right path for him is the right approach. There are plenty of very good software engineers and plenty of students currently studying in top universities and in top graduate programs who don’t even know and never did know what IB actually is.