I honestly think, if every set is compromised of at least 6 exs and 3 of them are megas at the end of 2025 we'd have ~20 megas (there could possibly also bigger sets with 8 exs and 4 megas.) so If we assume that's the case with every set until the end of 2026 we should have space for at least 50ish megas (assuming legends za will introduce new ones.) and this math is only with the lowest we can think of. Maybe at the end every mega gets a ex, via specialproducts, startersets and cards in sets. I'd really love that