Handle multiple dimensions among features/respect strict = TRUE

[paleolimbot]

A few options:

• Error (what happens now)
• Fill extra dimensions with NaN if strict is TRUE and there are extra dimensions
• Drop dimensions if strict is TRUE and the dimension isn't supposed to be there

Perhaps all of those (make a user opt-in to extra dimensions filled with NaN)? Either way, strict = TRUE is might not be respected or might give a different error because the schemas aren't compatible (clearly this isn't tested).