The difficulty for the Pilgrim Office will be the checking of the sum of kilometers which should reach 100km...
When I volunteered at the Pilgrims Office in Santiago in 2023, I checked the starting point in the pilgrim's credencial then the last 100 kms (usually Sarria-116 +/-) followed by the "2 cellos" in each of the stages into Santiago. If this was satisfied, compostela was issued. Othewise, I referred to the permanent staff. The computer at the Pilgrims Office has a pretty accurate distance listings, particularly of the popular starting points; SJPdP, Roncesvalles, Burgos, Ponferrada, Oviedo, Porto, etc. The only time the permanent staff had to approximate distances are when pilgrims started their pilgrimmage in distant places like Austria, Germany, Hungary, Netherland, Slovenia, etc and they use Google Map. The corresponding pilgrims were immensely happy to receive a Distance Certificate crediting them with a pilgrimmage of several thousands of kilometers!
For those who completed the pilgrimmage in not "continuous" walk, in different instalments, say different years, I checked where and when the different walks started and ended, followed by when and where the pilgrimmage resumed, leading to the "last 100 kms" into Santiago, and the corresponding required "cellos".
I strongly agree with
@AchimBerlin -
"Maybe we all should remember what the Camino is and ever was: a pilgrimage, an effort, a challenge, a way to find out about yourself - be it your faith, your perseverance, being alone or finding solace in nature or friendship with perfect and not so perfect strangers.
It’s not a picture perfect, planable holiday with a menue to choose from.
So if you’re religious, spiritual, sports-oriented, culturally interested or nothing of the above:
Just walk - and expect nothing but the unexpected."
Saludos y Buen Camino a todos.