Ken made a bamboo backed juniper (boo-niper) over on
PaleoPlanet. ERC is basically a juniper, so you can treat it as such. A bamboo backing can work just fine, but trapping it is a smart thing to do. Keeping the belly flat also helps.
Newindian, juniper is not the most compression strong wood there is. Its compression strength in numbers is nothing spectacular, actually. It's the very high elasticity of the wood that makes it so superior to many other woods. Since sinew is also highly elastic, that is why sinew backed juniper is such a great combination. Two highly elastic materials working in sync.