My Yusa deep cycle SLA quotes about 1/3C as max charge rate. It's 26Ah and quotes 6.5A as max current.
If the charger is asking for the nominal voltage that would mean it will manage boost, cycle and possibly equalisation. Unless you change those settings be aware they are often different for different types of LA battery. Flooded cell often accept up to 15V boost, 14.4V float where as SLAs are sometimes lower at 14.5V boost, 13.8V cycle or similar.
Sometimes these settings are hidden in the preference menu.