I am replacing a LMS522c on the console with a Elite 9 Ti2. I know that in order to keep the transducer up enough to keep it from damaged I'll probably lose 2D at higher speeds. Does it make sense to also keep the 522 on the console for a dedicated 2d since the transducer is a shot through hull and use the Elite for mapping, sidescan and downscan?

yes

That's what I do. I left my X75 and shoot through when I upgraded mine and just use it for depth when running and the 9ti on full map.

If you went up to LIVE unit, you could hook up both your 2D in hull and Active Imaging and have it all, but better to leave 522C for high speed sonar if you go with Elite Ti2, however you can keep some high speed sonar on our Elite 3-1 if mounted perfect. Nice thing about not depending on 3-1 to provide high speed sonar is you can place in a position that gives it some protection.

Rob, Is it possible to use the 2 transducers together on the Elite graph?

There is what is called the 'Y' Cable, but it has to be purchased as a package. You can check it out at Lowrance.com and see if the options fit your needs. I will send you a PM to call me if you have questions.