I think the Introduction could have a brief summary of survival analysis and analysis via DataSHIELD to give some context. And perhaps give an example of an analysis? You could always reference the legumes paper and say that it had to use the piecewise exponential regression. Describe how this approach helps overcome some of the disadvantages (it's an approximation, having to define the time buckets, lack of familiarity makes people suspicious etc). At this point you could also set the scope to being SLMA rather than full likelihood.