I'm not sure whether the adjustable ones adjust enough to cater for road callipers, they are designed more to provide different lever feel to suit rider preference with V-brakes.
Yeah I'm not 100% that it full correct the cable pull, I have not compared however it does make a significant difference. I've an only hack MTB set up wth the old LX levers, one canti one v brake and the canti works very well after flipping the little nob on the lever to alter the cable pull. The canti is set up with a high mechanical advantage though so having a slightly longer cable pull is probably needed. The lever and canti set up prob meet in the middle in cable pull requirements so to speak.
Yeah I'm not 100% that it full correct the cable pull, I have not compared however it does make a significant difference. I've an only hack MTB set up wth the old LX levers, one canti one v brake and the canti works very well after flipping the little nob on the lever to alter the cable pull. The canti is set up with a high mechanical advantage though so having a slightly longer cable pull is probably needed. The lever and canti set up prob meet in the middle in cable pull requirements so to speak.