What kind of stuff do you need 10 amps for, if you don't mind me asking? That really is quite a lot, and such a PSU needs an excellent (read "complex") project not to mess up your day.
There really isn't much of a difference between a 30 Watt and a 300 Watt lab PSU. The 30 Watt unit will need a solid thermal design, as will the 300 Watt unit. Tap switching may be implemented in both. Instantaneous SOAR protection is always a must, and so is thermal protection. Numbers change, parts change, but the design, the topology, is the same.
What IS different is that you will need multiple pass transistors in the 300 Watt unit, and you will likely need a beefier driver, or multiple drivers,
especially with MOSFET pass elements. And you might want a soft-start circuit, not only due to the large transformer (especially if it's a toroidal), but also because of the large filter caps, to avoid blowing fuses (or be able to use a
useful fuse rating, not 15 AT like in some Chinese 300 W supplies).
Oh, and failures during build / evaluation, if any, tend to be more violent in nature, as expected.