Answer in brief:

• In Svetambar (Shwetambar) Jain practice, the Samvatsari Pratikraman traditionally includes reciting 40 Logassa Sutras (40 logas) as a key Kaussagga part. This count is commonly equated with reciting 1008 Navkar Mantras in that ritual. The practice of using 40 logas for Samvatsari is described in Svetambar Pratikraman texts and is a well-established part of the ritual. Some traditions also describe other Kaussagga counts for different occasions, but the widely followed Samvatsari form uses 40 logas. You can read more here

• The origin of this 40-logas practice is attributed in later Svetambar tradition to a reform and propagation of Pratikraman with lay followers around 400–500 years ago, notably associated with Acharya Vijaychandrasuri in Khambhat, Gujarat. This is part of the historical narrative found in Svetambar Pratikraman discussions, though exact phrasing may vary in different sources. You can read more here and