On a standard 8-SOIC footprint without the pad connected, the part will run hotter and may hit thermal shutdown at high common-mode voltage or high shunt current. The exposed pad also serves as the return path for the input bias current — 175 µA typical — so keep the PCB layout clean under the part.
The MAX9918ASA+T is marked Active in production and is ROHS3 compliant. The ROHS3 compliance covers the full set of restricted substances, so it passes European and most global environmental requirements without an exemption.
It is offered in Tape & Reel (TR) and Cut Tape (CT) options — the CT option lets you buy single units or small quantities without committing to a full reel. For production volumes, the TR option is the standard.