Looking for advice on package for lazily evaluated kernel matrix on the GPU

I am working on creating a package for lazily evaluated kernel matrices, which will work on the GPU via KernelAbstractions. The idea is to create a central object (LazyKernelMatrix) which does not allocate and evaluates the kernel function k(x_i, y_i) only when necessary. This is quite easy to do on the CPU by overloading Base.get_index but my main goal is to implement matrix-vector multiplication (or maybe other functions) on the GPU, along with various sparse approximation methods, such as tha...