Are the dampers/shock absorbers, within the twin adjust projekt comfort coilovers, built by Koni for the Twin Project company? If so, are the dampers adjustable for damping?
Dropped vans are really not my thing but I understand, it has something to do with aesthetics? That the appearance is the the most important requirement? Then achieving the best handling and ride characteristics is always going to be a difficult and a compromised task. As Jog has stated, razing the height, will give more suspension travel and if the damping is adjustable, then, stiffening one click, might encourage the dampers to get a grip on things. You could try that. Perhaps one thing at a time and noting what the difference might be, taking note and so on.