The Siena School webpage states: "The aim of the school is to have the crystallographic computing experts of the present, help train and inspire a new generation of experts in crystallographic computing."
I am of the past, not sure of being an expert even about past things, not sure of being inspired. I learnt Fortran 66 in 1972 during an exciting 10 hours small course (programming for geologists), and still continue to use it in a not recent form (Fortran 77) which recent compilers continue to understand, fortunately.
Thus my advice to those who seek to encourage your scientist to write more than scientific algorithms is to do so with support and respect.
I am afraid that neither support nor respect depend on the algorithm writers. The advice has to be given to the decisioners in chemistry and physics (since crystallography has no legal existence in most countries) : stop to consider programming as an exclusive job for computer scientists. More about respect/support, you know the proverb : A prophet has no honour in his own country.
So, my advice to scientists in a position to do what they want is : do what you want if you think that this is the correct way. Not sure from where will come inspiration, maybe a school, may be not, anyway it will appear in your mind. Long life to the command line, concentrate on the algorithms ! If an idea looks good but you are not sure to be able to realize it, start programming, problems could be solved during writing the algorithm. If you think too much in advance to these >10000 lines of code, you will not do anything.
Best wishes,
Armel