I have 3+ year experience in ERPNext and developed 10+ successful project. You can see my linked in profile and up work profile for a completed project for more information. 2 maintenance contact for cosmetics company and juice manufacturing company. Recently completed customization for Mobile SIM distribution and water meter Bill management. 1 year before completed project for job placement lots other projects related to manufacturing company with multi-currency. We will make a custom app for this so you will not face any issue to upgrade next ERPNext version. If you want I can show my recent works, I want to give a suggestion that, you can develop a mobile app as well who can communicate with the ERPNext server.