I use tubed sealants all the time, have done so for years. When I task a new employee with caulking a joint, there is always a short instructional lesson. Dicor self-leveling is a bit different than most sealants as there needs to be sufficient material dispersed to cover the joint. The rate that it comes out of the gun is the critical part. That is controlled by the size of the hole cut in the application tube, the pressure supplied by the trigger, and the temperature of the sealant. The same is true for seams on siding but less material should be applied.
Most new guys cut an application tube too wide. I start these guys on a tip cut 1/8" wide, just enough to insert the pierce rod in the application tip. That way, a small bead can be applied and smoothed back into the joint without a big smeared mess of sealant. Proflex sealant is very stiff and can be tooled easily after application. Again, start with the least bit of material and control application rates with trigger pressure.