Is it just personal preference that you don't buy the locked maps anymore, or is there a specific reason?
I hate copy protected software, on principle
Years ago I used to do design consultancy, designing integrated circuits among other stuff. I spent about £10k on some dongled FPGA design software. Then the dongle broke, and the company said "it is no longer supported". Luckily for me, I found a very clever Russian programmer who cracked it, for a small fee
A lot of people burnt their fingers on copy protection.
OK, MM is just £20 or whatever, but the principle is the same. I never even install any such software, not least because the methods they use to stop people reinstalling trial versions etc leave all kinds of hidden garbage behind, which comes back a long time later to bite you.
If the CAA genuinely cared about flight safety, they would make these charts available online, instead of giving MM a monopoly like this.