LCA is paid like it is now, more or less, and applied only to the original credit. It won't be included prior to the "fly your ass off for an extra quarter" tiered pay scale credit adjustments.

A reserve LCA would get their 75 at straight pay, plus the standard LCA overage for their LCA trips, not 125% of their LCA-overide credit taking them above 75 hrs credit.

Sounds like this may be clarified or modified as part of the next LOA.

Example (I don't remember what LCA override is):
Regular CA: 78 block for 83 credit = 75 x rate + (83-75) x 1.25 x rate = 85 x rate
LCA: 78 block, 83 pre-overide credit, 10 as LCA = 75 x rate + (83-75) x 1.25 x rate + 10 x override (25%?) x rate = 87.5 x rate