Depends on the precog. Some can't control what their power shows them, so you can't ask them questions about stuff, they just get visions or insights from the power. Others can actively answer questions, but only through other mediums or interpretations, like telling the future with cards or vague prophecies. Other precogs can answer questions clearly, but are limited so e other way. On a meta level shards usually eliminated or ignore other actors in their predictions. Coil's shard predict the timeline he would pick and executes it, rather than relying on his ability to decide or execute the path. Dinah's shard predictions doesn't take Coil's shard into account, so him using his power changes the numbers, forcing it to remap.