I've had the same problem--twice--with the most recent one, I fitted a horn cleat each side, just for symmetry, really, but it also gives me the option of tying up either side. I leave a rope permanently run down each side when I'm operating from my normal ramp, so I can come in to either side of the finger, and just worry about getting the stern rope on, particularly when operating solo. There is a fairlead fitted to one side, for using mooring ---I left the boat on a mooring for three weeks, often in fresh wind, worked perfectly. Where I have actually fitted the cleats is the same thickness as where the original bollard was fitted, so no issues with strength.
The original mounting holes for the bollard were expoxy plugged, and the piece of starboard shaped over the top, to protect the deck from chain. Then later, I added a hoop through the front mounting holes of the bowsprit roller, so the anchor can't jump. I had a stainless u-bolt exactly the right size, as it turned out, so that was a lucky co-incidence.