I'm late here, but while it may create more problems than it solves (it also uses an ISO style vertical "7-shaped" enter key and splits the right side shift), a JIS keyboard shortens the spacebar and does 4-1-5 on the bottom row. If it's remappable you could make the one immediately to the right of space be another space so your thumb doesn't betray you.
Beyond that, "Minila" layouts are usually for smaller boards (60%) but will sometimes have this, and if you can at least go as far as soldering switches, YMDK sells a cheap PCB that has many bottom-row options. If getting left-Alt moved to the right a bit is the main thing, many custom and semi-custom boards support the "Tsangan" bottom row that scooches it so it covers 3/4 instead of 1/2 of 'X'. Finally, the Tex Shinobi is a mechanical keybaord that recreates the layout of a Thinkpad, including the trackpoint.
Or, you could go full DIY. C'mon! You know you want to!