hey there 
so i can highly recommend something for the workflow. i will concentrate on the dawless setup, since its additional stuff for you to maybe wanting to controll daw stuff by DT or else.
first, have the DT go in MIDI A. I think you dont even need the ch filter unless you want to add specific pipes/ functions to specific channels in your chain.
In the MH Editor, just do MIDI A IN to MIDI A OUT and MIDI A IN to MIDI B OUT.
For your setup, I recommend using CH9 CH10 CH11 CH12 in order for either of the machines. Thats for usability and visual feedback on the DT. Since midi a, midi b … on the DT is Trig/track 9,10,11,12… It could be SE-02 (CH9), TD3 (CH10),…
Set the DT to autochannel 14 (for example, any channel you dont use).
You also might wanna set the midi channels on each track on 9,10,… (DT internal)
Plug in your Minilab (CH14, your autochannel of DT) in MIDI IN B of the Midihub.
Route the MIDI B IN to MIDI C OUT. This way you can just select any of your midi or sample tracks on the DT, as if you would want to record something the usual way. (activate a specific track with your finger :D)
Now you play the notes in with the keyboard of the Minilab. Which gives you a keyboard with velocity and all the other great stuff for every track on DT you like.
I just seperated your machines on MIDI A OUT and MIDI B OUT. As far as I know you could chain them all together, but I think a bit of uncluster helps with potential midimess.
MIDI A IN (DT OUT)----------MIDI A OUT (SE-02 IN thru to TD3 IN)
MIDI B IN (Minilab OUT)-----MIDI B OUT (Volca IN thru Volca Bass IN)
MIDI C IN---------------------MIDI C OUT (DT IN)
If you now want to use the great potential of the Midihub for a specific channel/machine, you add a virtual pipe and route it back to the right MIDI OUT.
In the beginning I was confused of how the selecting in the editor works, so I just tell it again: you select every track exept the one you want to work with. So for example for CH9: CH9 will be the only unmarked in the list.
For the controlling of daw synth or else, just use MIDI A IN (DT) or MIDI B IN (Minilab) to Virtual A,B,C… it should work instantly if you open your daw and check on listening to midichannels.
Thats my basic setup without further midihub magic and I hope I was able to help you set things up for a start. Please ask, if something was unclear 
All the best,
ony