As a general note, to avoid a conflict with the second DMA controller ports, you should set sbtype=none in the .conf file when trying to use the Tandy DAC emulation.

Mickey's Colors & Shapes is trying to use the Tandy DAC, but it writes 7 to the low nibble of port 0xC4 and that does not enable DMA DAC in the current emulation.

Crescent Hawk's Revenge is using direct DAC output on port 0xC5, which is not currently supported. I tried a simple test (a hack, really) to forward the output to the Covox/Disney device, and the digitized sound seems fine:

1     case 0xc5:
2         switch (tandy.dac.mode&3) {
3         case 0:
4             // joystick mode
5             break;
6         case 1:
7             tandy.dac.control = (Bit8u)(data&0xff);
8             break;
9         case 2:
10             break;
11         case 3:
12             // direct output
13+            IO_WriteB(0x378,data);
14             break;
15         }
16         break;

On a side note, CHR's setup program thinks machine=tandy does not support DAC because INT 15/C0 reports a table length that is not 3, although it's just a warning in this case. I suppose old systems do have just the model, submodel, BIOS revision, and no feature bytes, so maybe that could be improved in the BIOS emulation for non-EGA/VGA machine types.

Perhaps these two games can be supported with further work on the Tandy DAC emulation, but probably not high priority because they work well with SB digital sound in DOSBox.