Regarding travel budget, why does Jems add automatically 22% of staff costs to the flat rate? When it is for EU locations the system indicates 15%. So is it possible for Jems user to change in this case 22% to 15%?

It is possible and mandatory to change the percentage of travel cost flat rate, namely to 15% for EU partners – simply click on 22 in the text box, delete it and type 15 instead.