You got it exactly backwards. R&D is not tax deductible, so the cheat would be to say the custom operator (=R&D) is maintenance and therefore OpEX and a fully

You got it exactly backwards. R&D is not tax deductible, so the cheat would be to say the custom operator (=R&D) is maintenance and therefore OpEX and a fully deductible expense. The entire problem is that software companies hire workers and need to deduct salaries in the month they are paid. The 5 year R&D rules basically say that your salary in one month must be tax deducted over five years. If your business is breaking even and making no net profit, you would now have to pay taxes, which turn your "break even" business into a loss making business. There is no situation where the old rules let you get away with paying less taxes than you should. The rules simply affect the timing of the tax deductions. The new tax rules basically assume every business has infinite access to 0% interest loans to bridge over temporary tax induced insolvency.