What's your take on this?
Check out this link for details:
Systemd escaping example (just keep in mind the differences between shell and other contexts):
and
OP, it seems you fall into XY problem[1]. So it would be great if you ask how to achieve your goal rather than getting people's thought about that systemd service file.
For many parts, the service file is similar with example on Bitcoin Core repository[2]. And while i may be wrong, i don't see benefit of bind mount with systemd rather than plain /etc/fstab.
[1] https://xyproblem.info/
[2] https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.service
Bitcoin nodes are usually only auto-started like this when they are parts of a larger application that uses Bitcoin data, like BTCPayServer - it doesn't create unit files for Bitcoin Core but you can do that easily though.
I don't know anyone who auto-starts testnet nodes though unless they are mining.