For 20 plus years, I have used wood table tops without a plate, height issues (lack of height, depth of cut). Polycarbonate plates, not bad, but no reducing rings, so you have to take care corners don't dip. and then alloy plates. All adjustments were from below with a home made height adjuster. Then I bought the Jessem router lift. There are not many products available in U.K. I put off making a table for both the Jessem and the Incra Ultimate for a while and then built 2 this year. The Jessem is great to use, setups are easily repeatable, it is safe and sturdy. A cranked spanner would be an advantage, but for bits up to 22mm dia I use a box spanner.