May not help, but knowing the stock settings can be a good baseline.

Fluid: Honda SS-8 fluid, 10W
Fluid level: 116mm from top (fork compressed, without spring)
Fluid capacity: 462cc
Preload setting: 4th ring from top
Rebound setting: 1.75 turns out from full hard
Compression setting: 1.25 turns out from full hard

The other guys are probably right about the springs being too soft. If you want to work around buying new springs, you could try turning in the preload adjusters and going with a slightly higher fluid level. More fluid in the forks leaves less compressible gas at the top of the chamber, which makes them firmer as they compress.

 

No, don't.... The fluid needs the room to go when the fork compresses. Once it runs out room, the tube won't compress any more and will cause the front end to become rigid and be very dangerous, until your seals blow...

 

I'm not talking about filling it to the brim. Just small changes of a few mL of oil still allows for the changes in volume as the fork works, but can affect the pressure which adds extra springing effect while compressed. I've tried it before in another bike and it worked for me. The fork was firmer towards the bottom of the stroke and much less likely to bottom out but still not not rigid to compression. It's not an uncommon recommendation/adjustment to use change oil volume change the properties of the fork in the later portion of the stroke, from what I have read. Seems to be more popular on dirt bikes though.

Not saying it is necessarily the best thing to do in your situation, but could be worth looking into or experimenting with.

 

Yeah, fork oil height adjustments have been a part of track riding for many years. But that's a bandaid at the track, not something you want to do all the time. So your both correct.