Scouts Canada in leader and clerk resources.

In leader and clerk resources there is a Boy Scouts section, but it's not especially useful for anyone outside the USA. In Canada for example, Scouts are aged 11-13, Venturers 14-18, so in the church we have 11 year old scouts for the boys who don't have the priesthood yet, then the 12-13 year old scouts, and everyone older than 14 is a Venturer. We also have cubs, which is 8-10 year old boys.

Are there any plans to expand the boy scouts section to suit the scouting programs in other countries?

I don't know what plans there may be but the structure you describe is not significantly different than in the US. The only difference is that 14-15 year old scouts are called Varsity scouts.

LCR already has organizations for cub scouts and 11-year old scouts but they are under the Primary organization because the Primary is responsible for those scouts.

You should be able to remove the Varsity organization and move all the members to the Venturing organization. The only problem is you may have to manually move scouts from boy scouts to Venturing. Otherwise it should fit your description. If LCR allowed you to combine Varsity and Venturing (rather than just removing Varsity) then the automatic membership rules should work too. That's an enhancement that you could request using the Feedback link at the bottom of any LCR page.

For those outside the US and Canada they don't have the Scout sections