A tube could be used to meet the protection rules, however if your intention is to sleeve ALC, consider the following:
Sleeves should not exceed half the tube diameter they are installed in, and the wall thickness should generally match; understanding small corrections may be necessary to accommodate commercially available tube and faster dimensions.
1.25"OD x .065" fitted with a .625"OD x .065" sleeve would yield a fastener through-hole of .495"; boring this to .500" would be reasonable.
1.00"OD x .120" fitted with a .500"OD x .120" sleeve would yield a fastener through-hole of .260", reasonable for a .25" bolt.
Please also remember the ALC is required to be continuous, (B.3.2.6); and actually sustains a significant amount of damage during competition.