Does the CX race matter to you? Are you likely to win or are there critical league points.
If you are going for a laugh then just go and watch. If it really matters then weigh up how much you think it is worth.
After the 3pks I had a bad cold. Missed a weekend of racing but decided that the following weekend I needed to ride despite a cough. Club hill climb and critical CX race (for me) in the same day. It would have been hard on a good day. I won the hill climb and coughed for the next two hours until the CX race. Hung on for third in what was probably the most horrible 50minutes on a bike I’ve had in a long time.
Felt rubbish for the rest of the week, not really able to ride hard at all – a headwind on my commute was a struggle. Still not sure I’m 100%. For me I decided it was worth the risk. If it was a one off race that I was making numbers up in then I would have not gone.