Typically the backtest of a quantitative trading strategy assumes a fixed period and fixed capital at the start to backtest a strategy. However, each strategy has a capacity (due to non-linear trading costs/slippage/commissions) beyond which adding any money to strategy doesn't improve performance and I think it is correct to measure the performance of strategy exactly with the capacity of the strategy as the initial amount and for a Minimum Backtest Length (see Lopez de Prado https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2308682) so that the risk-adjusted statistics are accurate.
Are there any references for this kind of approach? What are the standard models for slippage used in backtesting strategies daily OHLC data? Also, any thoughts on the correctness of this approach to backtesting the strategy are appreciated.