Everyone I know who's serious has separate road and Tri/TT bikes. The LD road folks run clip-ons on their road bikes, never Tri/TT bikes, because you have to climb and have many positions. I've been using clip-ons for 20 years or so. My latest iteration has these base brackets:
https://www.amazon.com/gp/product/B07D92763N
These brackets put the aero bars below the handlebars, which is a bit more aero, and have flip-up brackets for a bit more room on the tops. I bought this stuff piecemeal so I could get the exact aero bar extension length I wanted. I use my standard road position, works fine for me. I use all alu stuff there, cheaper.
Least expensive thing is probably buy Profile stuff for the road bike and get a used tri bike.