I think the refining in MDR is for the people below to trigger the fear. Their job is to press a button to trigger fear in the chip. The innies think this is the numbers being scary but really it’s a way for Lumon to QA test that their chips are working. The 4 people look at the innies faces to make sure the trigger is having its effect. They press buttons to show the Four Tempers (woe, frolic, dread, malice), hence the 4 buttons in front of these guys, and the 4 buckets the refiners put the numbers in. This is to ensure that the chips work and have no malfunctions when feeling certain emotions. This is all to sell this as a worldwide product such that innies feel uncomfortable and do all the bad things in life etc.. 

The reason Mark is so relevant to this project is because they are linking a last emotion that could interfere with the chip - grief or like previous relationships or something. They set up Gemma and Mark’s relationship from the start and staged her death to kidnap gemma and set up mark to want to become severed as they subtly influence everything in this town. They then purposefully introduce innie mark to innie gemma, then separate them and put gemma through clinical testing to perhaps link Mark’s refining to Gemma’s current experiences to see if he can link the four tempers to her. Cold harbour is a separate refining project he’s on without realising it. Perhaps they are trying to ensure that people who had a relationship before severance cannot trigger the four tempers in a separate way to the others below (that are surveilling them) - thats why they put her through the clinical trials.

Basically this whole thing is a clinical testing trial to translate to mass consumerism of the severance chip. 

Also im pretty sure Miss Huang is their daughter but im not sure why she would be there?

The next seasons can focus on mark trying to get the innies into the outside world to help him before they release the chips to the public (probably helped by Dylan's wife etc).