I'm not familiar with V.35.
NXP designs to an attachment unit interface (AUI) specification (MII, GMII, RGMII, SGMII, etc.),
so in most cases, proper operation is achieved if the interface signal requirements (timings, IO levels, etc.) are met.
This includes PHYless designs as well.
Input Output Buffer Information Specification (IBIS) modeling can help determine signal degradation to/from our device across the interconnect.
Actual medium support (copper, fiber, coax, etc) is dependent on the Medium Attachment Unit (MAU) connected to our device (PHY, Switch, FPGA, etc).
LS1046A supports RGMII, 1G SGMII, 2.5G SGMII, QSGMII, and XFI for the Ethernet protocols.
Do you intend to use one of these interfaces?