Correct. And I feel that Isshinryu is not the be-all, end-all. It just happens to be what I study. If I had landed at a Gojuryu or a Shorinryu or a TKD place, then I'd be studying that.
The more layers of the onion I peel back, it seems there are more layers to investigate. I feel I'll never reach the end of the possibilities, the learning. It just goes on and on. So yes, I would not turn my back on that to try to absorb something else. I'd be worse at both, rather than better at one.
I've often found that to be true in myself, Bill. More power to you if you are in a place with a stable school and instruction which isn't capping out, etc. I started at 8 with aikido, and my teacher, who was a young man, had to move to follow his professional career. I got into TKD early in college, and stuck with that through undergrad and up, and across a move to another city. When I was done with that level of school, I moved to Houston, and couldn't find a TKD school of the same association, so found a good school with another young guy with whom I assisted teaching TKD in exchange for learning HKD straight from him, sort of privately which was cool, and participating in the HKD classes as well sort of as a sleeper, is how he put it. Then came grad school and off I went again, and this time it was Muay Thai that was ready to hand and when that transferred out I carried the MT with me and got into judo. Landed in aikido after an illness from which I need some rehab, and have stuck with it... now the longest of any of my stuff, if you don't count my ongoing self-training in those as "continuation," which I really don't. It's just keeping the polish on the car and the engine tuned and making sure there is air in the tires.
At regular time/grade rank progression, if I could sidestep association politics, I'd be like a muckety-muck by now! But, I'd not have met my wife, so that's a no go. Also, I really have enjoyed the contrast between styles, it has been a fun ride.
Also, it's a good thing to know that someone else uses the onion as a metaphor.