When you cut longer pieces, miter saws are best used with supports on both sides. One way is to cut in a drop-down section into a bench for the saw. Another is to build up raised supports on both sides of the saw on top of the bench. An upright along the back of the supports will let you use a stop block for repetitive cuts.
If you are like most of us and not getting any younger, consider adding features to your kitchen that will ease the transition to the Golden Years. Rollout shelves reduce stooping and bending; raising the dishwasher an extra few inches does too. Add a heatproof landing area next to the oven and stove to reduce cross-kitchen carting of heavy pots and hot pans.