Cross Refence Limit Avoidance

Theory: Limits can be avoided using copy row automations

Test Run today:

Sheet 1 = Site A Items, 7600 rows, imported using Data Shuttle/Merge

Sheet 2 = Site B Items, 7600 rows, imported using Data Shuttle/Merge, multiple columns index matched from Sheet A, changes triggers a copy row to Sheet 3

Sheet 3 = Index match more columns from another dataset, row addition triggers a copy row to Sheet 4, then move the row to a "Garbage" sheet

Sheet 4 = Helper column to identify duplicate rows and move the older one to the "Garbage" sheet.

This seems to be working, Sheet 4 has all the combined information and not a single cross refenced cell, I just need to empty the Garbage sheet on occasion

Is this sound or is it going to come crashing down?