I’ve had the thought that it might work to caramelize the sugar (meringue sugar), then add water to dissolve, then bring it to 248F. But I haven’t tried it, don’t know if the sugar would get too dark, or if the altered chemical makeup of the sugar would mess up the meringue syrup, etc.
If you add caramel, that might work but would make it pretty sweet. Maybe use creme fraiche instead of cream to make the caramel.
You could also take a look at caramelized white chocolate- Rose’s blog, it’s a component to make Caramelized White Chocolate mousse. I don’t know how smooth the white chocolate still is after caramelizing.