How about releasing as "Lite" something that was two or three major versions back? No "serious" customer willing to pay good money will settle for that but it may satisfy the hobbyist just fine. So no "cross pollination" there. They don't really need to support it because its probably EOL'ed. No codebase issues because its just an earlier version. Makes sense to me unless one is more worried about "company image" considerations.
The problem with that is that even 10 year old PCB software will do what 99% of people want, hobbyist or professionals.
So you can't just release something like 99SE as freeware, it would ruin your current business (albeit awesome for the market).
You need to release your current offering just stripped of some features, so the users get a taste for your current offerings and have the incentive to upgrade as their needs grow. Hobbyists become well-heeled hobbyists or turn their hobby into a business, students become professionals, one-man-bands get bigger and better etc.
The trick is knowing how to limit it.
You have to give them the good stuff to get them hooked, things like 3D viewing and supplier integration for example.
Stuff like automated productivity enhancement are prime candidate to leave out, so autorouting, signal integrity, and some of the more advanced intelligent manual routing stuff for example.
Pin size and board size limit can be crippling, and oyu have to be very careful there. Eagle is a classic example of how to completely goof the size limits.
For the record, my advice to Altium is thus:
1) A completely free version. No restriction on how it's used, commercial or otherwise. No support, forum only. 2 layer limitation, 4 would set you apart from some others though. Maybe one schematic sheet limit (or two, to give them sniff of what harnesses are about). Maybe a size limitation, based on total area (if possible) rather than a fixed size. If you want to get radical, no size limit. PCB and schematic only, with full 3D and library support, and that vault rubbish included. No embedded or FPGA support. No autorouter. No signal integrity. No panelisation stuff.
Just enough to allow hobbyists, hacker, makers, and midnight engineers to get started and produce something useful
they can sell.
If you want your vault/cloud stuff to take off, you have to allow this group to use and contribute, they are the most passionate.
2) A low cost paid version, pick your price. $100 up to maybe $500. Paypal online buying only, no sales droids, forum only support.
4 layer restriction with no size limits, and more schematic sheets (say 10?). Plus you get panelisation and any other production level stuff. Otherwise similar limitations as #1 No need for embedded, autorouter, signal integrity, no simulation, or advanced productivity tools like FPGA pin swapping. But I'd give them the interactive autorouter stuff.
Just enough for the same crowd as #1, but they can produce more advanced boards for production.
3) Your current "all you can eat" offering with the subscription service and full phone/apps engineer support etc.
All of them get current updates and bug fixes, to give them all a sniff of how wonderful your subscription service is.
Dave.