Three paths — not one winner
- Excel/WhatsApp discipline: cheap and fast if the team is small and follow-up is already consistent
- Packaged product (SaaS or Odoo/ERPNext partner): faster when the template covers ~70%+ of the cycle
- Custom build (Rootk): stronger when the cycle is the edge, or WhatsApp/RTL/branches/collections sit outside the template, with client-owned code