Well, half-life of test enan is actually days, accurately based on the number of carbon atoms. Quoted half-lifes in the BBing community are way-out from the medical community. As for how long it would take for "gains" to stop, that would be when your blood levels return to "normal" levels and below, which massively depends on how much you have been shooting. If you've been shooting 1g/wk, it takes 5 weeks for levels to stabilise (. what you shoot on week 6 would give the same blood levels as what you shoot on week 5).... and then takes around 4 weeks for levels to return to average natural levels.
Controversy first arose when the French-owned and Montgomery County, Maryland -based Keolis (already operating Virginia Railway Express trains) was the only bidder for the contract. The bidding process was suspended in the fall of 2010 due to lack of competition. Before bidding reopened in 2011, Maryland passed a law (at the request of Leo Bretholz and other Holocaust survivors) requiring Keolis's majority owner, SNCF (currently solely owned by the French government)  to fully disclose its role in transporting Jews to concentration camps during World War II (while SNCF was under control of the Nazi government), to the satisfaction of the Maryland state archivist, before Keolis would be allowed to place a bid for MARC service. Keolis faced similar issues while bidding for VRE operations in 2009, but in the end, they were allowed to run VRE.