You can still get to your old stuff. It will be in a cloud which is your personal Two Notes license. And you will still be able to get to it in your wall of sound because you have to be online to access your online stuff. You only need to download it or upload it to your C.A.B M+ or Remote respectively if you want to be able to access it offline. Once you have purchased or otherwise obtained Two Notes IRs, you will never lose them. They will always be accessible.
I have a C.A.B. M+ that I use with Captor 16. I swap out cabs on my C.A.B. M+ all the time. The 1st thing I did when I got it was go through it and delete all the IRs for bass so that I could make more room for guitar IRs. There are only 30 something slots for cab sims on C.A.B. M+, but there is room for up to 99 presets. Presets are cab sims combined with whatever personal settings you use with them and then save in Remote or Wall of Sound. I use them to create the EXACT sound/tone I am going for in my head. Its amazing the different tones you can get by a tweak here and there. A little goes a LONG way when you're talking mics and mic position. The only restriction for a preset is that it be created using one of the 30+ cabs within my C.A.B. M+. It all starts with the cab sim, but can go anywhere from there.
Having my Captor 16 and C.A.B. M+ has opened up so many new doors and has been extremely inspirational for me. I have begun to even record what I am playing when I practice. Then I use my plugin with my recording to try new cabs and then tweak the cabs I like. Its kind of like my reward for practice. After playing for 22+ years, practicing isn't always something I want to do. There are times when I tell myself I don't need to practice. Thats just crazy, because when it comes to playing guitar, it all begins with the hands. They are the best "effect" I have as a guitarist. So this routine I've gotten into just gives me something to look forward to when I'm finished with my hour (half hour at the least) of practice for the day. Doing this also allows me a time to do one thing and a time to do the other. I have to separate them, because I have ADHD and I am OCD as can be, and if I allow myself to tweak whenever, I will end up with option paralysis and I would never play a thing for sitting there spending all my time trying to get a particular sound. It also helps me to keep things fairly minimal. After all, it the end its all about making music and actually playing guitar.