The lease rate is an interest rate (ie, based on time) in addition to the absolute minimum payment of the dividends issued. It is set by the market: there is a limited supply of shares available to be borrowed for shorting. For most stocks it is about 0.3% for institutional investors, but 5% for a tenth of stocks. The point is that this is an asymmetry with buying a stock.

Now that I look it up and see that it is 0.3%, I admit that is not so big, but I think it is larger than the repo rate. I see no reason for the lease rate to be related to inflation, so in a high inflation environment, you could make money by shorting a stock that did not change nominal price.

(Dividends are not a big deal in shorting because the price of a stock usually drops by the amount of the dividend, for obvious reasons.)