I thought some version of 3.x was the first to support hfs?!?!
System 2.1 to be exact, which required the HD20 INIT on the 512K (the 128K cannot load the INIT). These are indeed all HFS issues. In addition, the 128K ROM changed some things related to the system. Stuff that was previously in the System was now in the ROM, but duplicates were left to support the 64K ROMs up to, but not including, System 6 (the first signs of system bloat). System 3.0 onward supported HFS, but more specifically Finder 5.0 was required. Alice likely required 64K ROM resources and once those began to be eliminated from System code, the proper calls could no longer be made. System 3.2 is the last which will run on a 128K, and 4.1 the last to run on a 512K. So that is the last likely system to support Alice.
For the record, the Plus, SE & Classic will all boot from System 1.1. In my experience System 1.0 (out for barely 3 months) is so ROM specific and buggy that it will not handle the 128K and later ROMs properly. 1.1 will support all of those Macs properly as MFS. Since it will not read HFS disks, you run the risks of losing data on any HFS disk. NEVER mix HFS & MFS environments for this reason, except for backward compatibility. The problem is the later ROMs understand HFS even though the System doesn't so the disk does not come up as "unrecognizable" tricking you into using it. Nevertheless, this is a handy setup for formatting 800K MFS disks for use with the 128K & 512K as well as formatting the HD20 for MFS only use with a 512K (the 128K won't load the driver).
So in using vintage Macs, the following applies to the Plus, SE & Classic. As long as you don't ask the System to use hardware of which it isn't aware or with software that does – in fact all three models can be configured to run with 512K RAM thus when using earlier MFS systems, making them virtually indistinguishable:
System 1.1 through 2.0 for MFS only, NO HFS support, SCSI support, PDS support or display brightness.
System 2.1 through 3.2 for HFS, SCSI support, NO PDS support or display brightness.
System 4.0 through 6.0.2 for HFS, SCSI support, PDS support, NO display brightness.
System 6.0.3 through 6.0.8 for HFS, SCSI support, PDS Support, Display brightness.
System 7.0 through 7.5.5, not recommended for MFS support.