That was it. My config file had it set to 512 and after changing it to 1024, it compiled as quickly as usual.
On a side note, my system has 6 GB of RAM. I'm not sure if the 512 MB is just a default or if it is based on available RAM and set on first run, but perhaps you could consider changing the default to 1024. That or maybe add it to the 'Tools>IDE Options' menu right next to Configure Process Timeout - or just put both settings in a small 'Advanced' window.
Just a thought, and I'm definitely not complaining about a manual edit. Just reading about all of the improvements made to B4A over the past few years while I was away has got me pretty excited. But then, I'm a bit of a geek.