From what we have seen, users can test beyond these limits however there may be issues depending on your EA and how it utilizes memory, etc. Your best bet is to test with the size of data set that you need and if you encounter any problems (eg. out of memory errors), try test with smaller subsets of data to see if that addresses the issue.
We've just tried a test by exporting EURUSD from 2008-2022 (approx 18GB FXT) and successfully run 2 passes on the Strategy Tester using "MACD Sample" EA. Of course, the point is not to negate what you are saying but it does highlight our usual recommendation to adjust your testing accordingly if there are problems.
Unfortunately given that we don't have access to the MT4 Strategy Tester code, we can't really offer any solutions to fix it but we believe it may be due to "excessive" resource use.
The best way forward from this point-of-view (and from an over-optimization standpoint) is to ensure your datasets are smaller.