I would suggest (in addition to the changes being contemplated here to solve the "India problem") imposing a negative interest on Wealth balances (both positive and negative, but more negative on positive balances).
An economy can only reasonably "save up" so much productive capacity before it begins going to waste - people do not keep building inventory that is not consumed; eventually they curtail production. And not-producing today does not increase your factory's ability to produce tomorrow; that potential production is simply lost. While it is possible to accumulate reserves of real capital, this too has its limits: Skills that go unused decay, capital stock becomes obsolete, and the institutions needed to run complex industrial supply chains dissolve if they are not occasionally exercised.
Similarly, on the other end, if you overclock your economy for long enough, it becomes the new normal. Workers write off the vacation they have accrued from working overtime, preventative maintenance backlogs on capital equipment is erased when the equipment breaks and is replaced, on-the-job training replaces formal education, etc.
This also imposes a soft wealth cap: If positive balances attrition at ten per cent per year, then an economy that "saves up" a quarter of its "income" would converge on a reserve that would allow it to double its production for three years without incurring any penalties (all else being equal). Which seems reasonable.