Any risks with always setting 'JS_BINARY__CHDIR' to '../../..'?

[refi64]

I use Bazel to build my personal site, and I've undergone a bit of a migration to try and use aspect.dev rules for all of the JS-adjacent tasks. The migration has generally gone well, but I'm a bit confused as to the best way to handle the binary directories.

I have a bunch of rules that run JS that I can't trivially use js_run_binary for, because I need to work with various providers in the deps and outputs. The main issue is, these rules use ctx.actions.args() + param files to add arguments, e.g.:

    args = ctx.actions.args()
    args.use_param_file("@%s", use_always = True)
    args.set_param_file_format("multiline")
    # [...]
    args.add("--metadataFiles=%s" % ";".join([file.path for file in metadata_files]))
    args.add("--postFiles=%s" % ";".join([file.path for file in post_files]))
    args.add("--output=%s" % output.path)

    ctx.actions.run(
        arguments = [args],
        # [...]
    )

Bazel auto-converts the the args reference to point to the path to the args file...and therein lies the problem: while I can adjust the paths inside the args file, I cannot adjust the path to the args file itself.

While playing around with this, I noticed two things:

• The oft-recommended chdir argument to js_run_binary works by setting JS_BINARY__CHDIR. I'm pretty sure I'm not supposed to set this myself...but I can, and this is a rather small project so I'm okay with some ugliness.
• The value of BAZEL_BINDIR seems to always be bazel-out/<arch>-fastbuild/bin.

So...I can actually get this to consistently work in my rules by just setting:

        env = {
            "BAZEL_BINDIR": ctx.bin_dir.path,
            "JS_BINARY__CHDIR": "../../..",
        },

The thing is, this feels...wrong? Like, the docs emphasize the trade-offs regarding paths a lot. Is this even supposed to work, or is it only working by sheer luck? Are there major risks in here I'm not aware of?