Nothing wrong with an editor per se - there's no copyright on sending whatever MIDI messages you want from a plugin of your own design.
You need to be more careful with panel designs, logos and trademarks because those are legally protected.
Having said that, it's very unlikely that the manufacturers would object - having a nice editor available makes their flashy hardware even more desirable to their potential customers, so I'd have thought they'd be more likely to see it as free marketing.
Feel free to use any schematics and algorithms I post on the forum in your own designs - a credit is appreciated (but not a requirement).
Don't stagnate, mutate to create. Without randomness and serendipity the earth would be just another barren rock.