We also used to disable LOH to reduce the binary size.
Moving it to addPreEmitPass2 also seems reasonable. Although the uncompressed size might remain similar to when LOH is disabled, this approach can enhance the compressed size because the linker will emit more NOPs.
As a side note, if we aim to reduce the size further in this context (without emitting NOPs), tools like BOLT or other post-link optimization techniques could theoretically accomplish this.