Crossaccess - import/merge of access permissions

My work on the Nodeaccess module is approaching a point where I'll be satisfied with it, and so I'm looking forward to some other projects. This particular one involves Nodeaccess and potentially several other node access modules, so I'm hoping to get some discussion here.

Fairly recently I updated the HIIT primary web server from Drupal 4.7.11 to Drupal 5.7, and while I was at it, I migrated from Simple Access, which I was never entirely satisfied with, to Nodeaccess - which didn't satisfy in other respects, but I've been able to fix that. But the migration was a bit of a mess. I can write my own SQL code, and since I only had one access group for each role in Simple Access, the operation was fairly straightforward. But for many admins, migrating between node access modules and keeping all permissions intact is a pain.

My suggestion is that a new module be created - my candidate for naming it is Crossaccess - that imports permissions from one node access module and merges them with those of another. All the module is for is to help people who for some reason need to switch to another module, perhaps due to their own module not being ported to a core version they require, a feature they want that another module has, or their module simply being abandoned and receiving no more updates.

Right now we've got four node access modules which do pretty much the same thing, with some differences in their UI and/or functionality. The ones I mean are: Node Privacy by Role, Simple Access, Content Access and Nodeaccess. All four grant access to nodes based on role membership. In Simple Access access is in fact granted to access groups to which roles belong, but it comes down to pretty much the same. Content Access can also give access to users with the ACL module, and Nodeaccess does the same natively. There are plenty more access modules such as Taxonomy Access, but they do their stuff in a different way.

I don't mean to try to steal the users from any of the other modules, in fact I think it's a good thing that we have some competition - that gives users diversity to choose from. In my vision, Nodeaccess starts to look more and more like a Swiss army knife with its configurability, but it's probably overkill for several users. I'm just of the opinion that users should have that choice, even after they've started using a module and decide they don't like it, but they don't want to give up the work they've already put into giving permissions to their nodes.

So. Thoughts, ideas, suggestions?