A two-magnitude slowdown by being too simple to make compilation/any form of not-naive interpretation possible, by preventing code from self-clobbering, isn't a

A two-magnitude slowdown by being too simple to make compilation/any form of not-naive interpretation possible, by preventing code from self-clobbering, isn't a great start either. The approach there is to write a faster "device" in the host language, which doesn't help portability.