There are several synonyms for the phrase "all during" that could be used to add variety and specificity to your writing. Some alternatives include "throughout," "during the entirety of," "across the span of," "from beginning to end," "from start to finish," "for the duration of," and "continuously throughout." Each of these phrases connotes a sense of sustained or consistent activity over a given period of time. Depending on the context of your writing, some synonyms may be more appropriate than others. By choosing the right words to convey your ideas, you can make your writing more engaging and effective.