This is fine to fix. Can also likely work around:

partial struct Money :
#if !NETSTANDARD
    ISpanFormattable,
#endif
    IFormattable

Or:

partial struct Money
#if NET6_OR_GREATER
    : ISpanFormattable
#else
    : IFormattable
#endif

Good point, didn't think of that tbh.
Another one, before:

public readonly struct BigDecimal : IComparable<BigDecimal>, IEquatable<BigDecimal>, IComparable, IFormattable
#if NET7_0_OR_GREATER
#pragma warning disable SA1001 // Commas should be spaced correctly
    , IFloatingPoint<BigDecimal>
#pragma warning restore SA1001
#endif

After:

public readonly struct BigDecimal :
#if NET7_0_OR_GREATER
    IFloatingPoint<BigDecimal>,
#endif
    IComparable<BigDecimal>, IEquatable<BigDecimal>, IComparable, IFormattable

That works for me.

Given that there is a suitable alternative form that avoids the warning, I'm fine with this being closed if you don't think it is needed. I prefer the suggested workaround anyway, the leading comma bothered me haha.

I'm leaving this open because it's fairly standard for us to ignore the end-of-line/beginning-of-line rules in the presence of preprocessor directives. We could either ignore all directives here, or we could just ignore conditional directives (#if/#elif/#else/#endif). I think I lean towards the latter.