Getting paid twice for the same freelance work

i do graphic design freelance. i have two clients in completely different industries who both need the exact same type of work. social media templates, brand assets, monthly content packs. the deliverables are basically identical in scope and effort.

eight months ago i realized that the work i was doing for client A could be slightly tweaked and sent to client B. different colors different logos but the structure and layout is the same. takes me maybe 20 minutes to adapt something that took me 3 hours to build from scratch.

so now i build one set of work and send versions to both clients. they're in totally different cities different industries and have zero overlap. there's no chance they'd ever see each other's stuff.

the thing is client B actually pays me more for the adapted version than client A pays me for the original. i asked client A for a raise six months ago and got told the budget is tight right now. meanwhile client B offered me a rate increase without me even asking because they said my work has been consistently great.

been doing this for eight months and both clients are happy. i'm doing half the work for double the income and nobody is getting short changed because both clients get exactly what they asked for on time and at the quality they expect.

i feel like i found a cheat code and i'm just waiting for something to go wrong but so far nothing has.