Why would I spend 10k on a 1/5 chance of getting a gold token when i could get 20 standards for 500iso each and have a better chance at getting a 3star?
Yeah, 10k ISO-8 is way too high, for practical and statistical reasons, but I see no reason why this couldn’t be a thing, other than whether they would deem it worth the time investment for such a low impact.
I gamble tons of ISO away on standard cover draws for 3*. I tend to average one 3* every 20K - 30K ISO.
If your main focus is story events and you largely ignore versus it’s worth it to have a wide variety of low level/power 3* over a strong 2* roster.
The more essential characters you have the farther you can go in story events for the 3* progression/placement rewards.
And every 2* cover you roll is 50% of your investment returned, while 1* still net you a 20% investment return.
But as far as the option of having a Heroic or better ISO draw, it would have to either be statistically equivalent to the standard draw rates for anybody to bother using it, or better which would result in nobody ever using the standard option anymore, so either way a moot addition I would think.