Short answer: Yes. Move along if you don’t care to sweat the details.
Many, moons ago I posted this nugget and a couple months ago I saw an interesting thread that wondered out loud if the fact that we now do client-side rendering changes this rule of thumb. A lot of folks now take it for granted.
Good news, it doesn’t. Even when doing client-side rendering in the browser, the lion’s share of the heavy lifting happens on the Server. Querying of the data source and creating the presentation model are server based. The browser simply draws things at the correct X/Y coordinates based the model which was created and lives in-session on the server. Those models can be re-used, and are more likely to be re-used if of a fixed size.
So keep setting exact height and width, campers.