No problem, check page 39 in the manual where it explains the RCV CTL function. Basically you select a parameter you want to control and assign a midi CC# you want to use to control it. Then in your midi controller you need to configure the CC messages to be sent for each preset.

Now, although the gap when switching presets on Space is a bummer, it's almost understandable considering the complexity of some of the algorithms, the real gottcha is the fact that it resents the preset even if your already on the preset! You not even telling it to change the preset but if it receives a program change whether you already on it or not it will reload giving you that painful gap.

My setup is the same as your splitting out my signal to run my delay and Space in parallel. What I've done is: Assign Space to a midi channel the does not receive program changes. Configure Space to receive CC messages for the parameters I want to control. Configure presets on my controller that send CC to Space along with PC and CC to all my other gear.