We run #25 chain on theoretical center distance without tensioners all the time. Alignment is key. The chain wants to jump when the sprockets aren't axially aligned properly.
Placing these holes can be done with a manual mill. No particularly high tolerance process is required. +-0.005" will work all day long.
Example Chassis with untensioned #25 chain runs.
FRC118 ran this setup for 2013 with zero maintenance issues or chain failures.