I own 2 OT and 1 MnM…I try to integrate it with MnM… but for melodies is better to do it first on the 303… Because once you do a pattern with the MnM and u go in pitch mode with the 303 is very hard to play on the MnM…
Then the other method that I use, as you do already I route the output of the 303 in the OT and play with the effect 