Is it ok to trim the roots if they create a blockage?Updated a year ago

It sure is. A good technique to achieve this is to lift the lid as far as practical and run a knife along the edge of the offending root system. Then remove the cut section.

If you intend on removing the plant in the not-too-distant future, simply slide the roots across to create a small channel. This should give a few days before they cause a blockage once again.

If your roots are very large it may be an indication that it's time to completely remove the plant and replace it with a new seedling.