Possible to view select POIs?

I am planning a route across France, Spain and Portugal, where POIs abound. My current approach is to generate a general route with the assistance of cycle.travel, and to compare with UNESCO's World Heritage map, as it might be disappointing to ride just a few kms past a major historical/natural site, oblivious to its existence.

There are so many features to cycle travel that it might already be possible. 

What do you suggest?

Merging saved rutes

According to this post (https://cycle.travel/post/4519) merging isn't supported, out-of-the-box. 

Is there a workaround other than download/merge/upload?

Forced routing

I am trying to create a route that'll use a known 4WD track that isn't completely mapped. Is it possible to force line-of-sight routing between two points. I saw this post referring to a "Go Directly To' option that I can't find. Deprecated? Suggestions?