It depends on what shock bodies and what rear lower arms you are using.
With the FS arms(if you can get them) and the stock shocks, you won't be able to compress them that much.
With the new rear arms(RS and JS) and the Tamiya,Top Photon,3racing, Asso shocks you can compress them so high.
Nothing to worry about.
Gives you more shock travel and less flipping when riding the curbs

regards Roy