Just thought I would post this again as i never got an answer.
I am running the latest versions of both Renoise and Microtonic.
However , the VST3 version does not recognize mutli mode, The stereo channel works on both versions, and the multi out version works on VST2, but not on VST3.

Any suggestions or is this a common bug?

HELP!

I can confirm this, also using the latest version of Renoise and Microtonic VST3, although I fear this may be an issue with Renoise. I say that because I can use Microtonic and Microtonic Multi without any issues in Bitwig.

In Renoise and Microtonic Multi, there is no audio coming out of any of the outputs other than 1/2 no matter how I route them.

With the regular Microtonic version, I cannot assign any sound to output B no matter how I route it in Renoise. I also get this popup message when I hover over the B output button, even though the output is assigned in Renoise:

Ya it's a bit of a weird one. Never had the problem until installing the VST3 option. However the VST2 works fine so i guess it's not really an issue. I never noticed the A B problem either, as I just checked it out. Works fine for me in the VST2 version though, so looks like VST2 it is. VST3's are notoriously a bitch to program i have heard as you have to put some sort of wrapper around it or something. The same guy said that effects in VST3 are not problematic at all, but synths and drum machines can get confused.
PS..thanks for the reply.

I have also read that porting things to VST3 is an undertaking, and so is support of VST3 in hosts, like DAWs. Renoise's support for VST3 has issues, from my experience mostly with UIs, and I wouldn't be surprised if other issues were presents.

Duly noted!
Not to worry much as I can still use Microtonic for what i need it for. I tend to use Waldorf Attack for drum synthesis mostly anyways. I like the FM option, sample mixing and dual oscillators. Not to mention Renoise is rather good for such as well.

You have any music out there made in Renoise?
Here is my Soundcloud. Probably the first 10 tunes were made in Renoise. The other ones were with my old hardware set up, based mostly around an old MPC, a couple of synths, and outboard effects units.
https://soundcloud.com/papadumtek

Take care!