unable to deploy sip-for-me on a typical java phone(with small heap size)

hi,

typical phone has limited heap size for java MIDP. Most  Nokia S40 
models only support < 500 KB limit for jad+jar.

we also failed to install sip-for-me on a lastest Sharp model (3G 
phone), due to max heap size limit again. in fact, it crashed totally 
:-P

in my research, only a few Nokia S60 models (N91,N80)  and recent 
SonyEricsson models  (K700i, M600, etc)  do support unlimited heap 
size. yes, only for these high end toys.

Nokia's strategy seems going to include SIP stack in S60 v3 edition OS 
layer from now on, so that developers can implement SIP enabled MIDP in 
roughtly 70KB,  but I do not see any other manufacture is pushing SIP 
stack as well. very sadly, I do not see any SIP related roadmap from SE 
so far.  (pls correct me, if i am wrong)

Motorola is pushing MSA  in JCP.  MSA includes JSR-180 but it is hardly 
 see any MSA capable phone in the market any time soon.

now , i have doubt:

1)  for the millions and millions of existing java mobile phones in the 
market, how can I 'squeeze'  sip-for-me  (~600KB) into perferable 
~100KB-200KB MIDP ?

2) no doubt that telecos industry is moving towards IMS world, but it 
seems that only Nokia, but no one else, is pushing SIP enabled phone.
will anyone actually bother IMS if without SIP mobile phone? i really 
do not understand what is going on !!!

pls advise me.

~manchi