Propper use of pins CLKx, LVDSCLK2p

Hello together

I want to use the EP1C3T144C8 FPGA for a design. Now there are two pins 92 and 93 still not used and I am thinking about to choose it as digital inputs.

After reading the device manual, I am now not absolutely sure how these pins can be used. With Quartus Web I get no compilation error.

So is it possible to use these pins as digital inputs and if yes do they have the same characteristics (e.g. regarding speed) in comparison to the LVDSxx-pins? Are there any points to consider?

Thank you for any hints and friendly regards

Geri