I think all parties in this discussion are correct in their own way. As I see it, the brim speed is always faster than the 'model' speed of the first layer but it is changed by the mm/min printing speed and first layer speed percentage.
In my case, I get a nice first (model) layer when I print at 50% for the first layer speed, but this makes the brim print too fast and it often starts to tear and roll. If I drop the first layer speed to 25% then the brim speed is also halved and now prints very nicely at last, but the model portion of the first layer takes an age to print. (25% is probably a bigger drop than I really need but it is a good confirmation of the situation)
I think Pavel is correct to question the logic behind this situation. Printing the first layer well is critical, any problems here will be fatal. For Simplify to acknowledge that there is a need to print the first layer slower than the rest of the model, but then make a distinction between the model and the brim is silly. The printer does not know or care what is model and what is brim, it is all just plastic that needs to be printed. The mechanics of printing will not be different for tracks just because they are destined to be brim or model. The user should have the ability to control all the parameters of that print process without having to sacrifice one (model print speed) just to get to another (brim speed) indirectly.
I would suggest that there be the ability to set the brim speed independently of the first layer speed - or perhaps better, as a percentage of the first layer speed.