Hi and welcome. I suggest you switch to half inch shanks. I get half inch grommets and drop them into the bottom of the collet space, they're about 1/8 th thick so you can just bottom out your bit on top of that. Not familiar with Ryobi, but removing the spring is pretty common for using plunge routers in a table. Just put the spring in a safe place so it doesn't get lost. How you remove the spring is another question, but generally there is a screw on cap at the end of the tube. That should give you another inch or more. With the half inch shanks, that should get you going.
For any bit much wider than an inch and a quarter across, get it with a half inch shank. The collet gets a tighter grip (more surface area for the collet to grip). Why such a fuss about half inch shanks for table use? Because that extremely sharp bit is spinning at 20,000 rpm and if it get spit out, it will tear up anything or anyone it hits.