
Q1: I’ve looked for “faucet supply lines” to the specifications on the tag but none of them fit this bottom connector look, has it been modified or do I need a speciality line?

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Q2: I’ve seen recommendations for 2 hole faucets for this situation, but with copper tubing I wanted an at least somewhat experienced opinion before I started ordering. What do you recommend for this type sink?

Thanks for the information.
Instead of the plug, you could get a soap dispenser for $25-30.