please enable UMB for internal allocs

[stsp]

Hi.

I built the prog with ia16-gcc in -mdosx mode.
I have plenty of UMBs, precisely ~160K, which
is much more than the program size.
But unfortunately, even if loaded with lh,
the prog eats quite a lot of conv mem:

ADDR(LOW) PARAS  OWNER
009c:0000 0x0200 [COMMAND - Data]
029d:0000 0x0121 [COMMAND - Data]
03bf:0000 0x00e6 [COMMAND - Data]
04a6:0000 0x0017 [FREE]
04be:0000 0x0d6a [FREE]
1229:0000 0x8dd5 [FREE] (END)

Would it be possible to enable UMBs
when allocating? I use this to enable
UMB:

static void link_umb(int on)
{
    asm volatile("int $0x21\n"
        :
        : "a"(0x5803), "b"(on)
        : "cc");
    if (on) {
        asm volatile("int $0x21\n"
            :
            : "a"(0x5801), "b"(0x80)
            : "cc");
    }
}

And then I can do:

    link_umb(1);
    db = _DPMIAllocateDOSMemoryBlock(size);
    link_umb(0);

... and that goes to UMB.
But there are some allocs during startup
that are not done with UMB enabled.
Can this be fixed?

Also I wonder if I can free the startup and
cw32 code by hands before executing another
prog. Is that possible? I'll use asm for an exec,
so I can free most of everything. Is that possible?