"Cross-chaining" is sorta, kinda possible, but not good, on a bike with a long chainstays. Cross-chaining on the short chainstays typical of today's "pretend" racing bikes puts tremendous wear on the cogs, and greatly increasing the level of friction in the drivetrain.

I don't "cross-chain", and some of my cogsets are twenty years old, and in good shape. A "cross-chainer" is gonna be needing a new cassette every year or two.

I knew a kid learning to shift a car who drove all the way to campus in first gear. Don't confuse what is possible "possible" with what a device is designed for. Richard Ballantine has written that he suspects that the only reason "cross-chaining" is even "doable" is for legal liability reasons: bike makers have to assume that someone is gonna try it, so must design their drivetrains to allow it to be done safely.

A properly designed drivetrain does not require "cross-chaining" to select gears that are actually needed by most riders. If you must "cross chain" to get to a gear that you need, you need a different cassette, or different chainrings.