No problem if you have mistake in filling in form. I did the same mistake on couple of places for ILR tier 1 PBS dependent route and got visa same day. Here is what I did once I printed the form and realized that I commit mistakes.
1. I emailed home office at
Public.Enquiries@homeoffice.gov.uk explaining the error with case reference number.
2. Home office replied my email in 2 days saying we have informed case worker about your errors.
3. Case worker emailed me in the morning on biometric appointment to send all the supporting docs about your mistake.
4. I mentioned all errors in the cover letter, printed online from, correct errors with pen and signed under the corrections.
5. Using new service I uploaded all documents on Sopra website.
ILR issued in 2 hours after biometrics as I used super premium service.