I discovered a possibility of extension to the M303 that might interest you with MI Warps + Soundmachines LS1lightstrip... see the Mylar Melodies video below.
Note the final budget, but you apparently will get a true enlargement of the 303 spirit. It’s very surprising...
For my part, I almost opted for the Behringer TD-3 simply, as I had indeed done with the RD-6. But, from my point of view, if drum machines (like mixers) are more obvious and tactile in a traditional desk solution, I have preferred 2 basic modules to combine with other tools I already have (like Optomix, modDemix, Synchrodyne, Bloom...). That's an inexpensive solution and takes little space too (6HP): Pico VCO2 + VCF1!

'On ne devrait jamais quitter Montauban' (Fernand Naudin).
https://soundcloud.com/petrus-major/tracks