Could it be a solution to carry out the project including the backtest with another platform and then replicate it on MT4?
It could be possible (we use MultiCharts with IQFeed - free trial. Also TradeStation is valid), but in practice it is difficult to work for:
1. portability: we are not sure that making the strategy in EasyLanguage will then be possible to bring it 100% on MT4
2. data: it is not for sure that the data you use for the strategy in easylanguage are the same as in MT4 (in theory yes, especially with futures, but with forex, for example, every broker has its quotes, and this greatly impacts the strategy )
If your capital is over € 5000, trading will always be just a hobby and then it's OK MT4.
If you have 15-20,000 or more, you should probably invest in a more solid and professional infrastructure than MT4.
See also the videos: