So let's recap. You arrive on time at 1930, then before 2100, you get your bags and clear Customs as a domestic pax, go back up to the ticketing/departure level, deal with the Friday evening rush to recheck your bags (if you are a Lan premium pax or have OW status, go to Lan's separate First/Business/elite section at the far left end of the terminal) and then the evening rush to get back through Immigrations (Lan premium pax have their own Immigrations checkpoint). Sounds stressful but it may work out.

If not, it's been a while since I was in the Pacific VIP Cub at SCL international side so some aspects that follow may have changed but aside from the fishbowl aspect (you are on the same level as the gates, shops, etc. and can be scrutinized by the passer bys) it was comfortable. Has wifi, bartender operated bar not serve yourself, no snack selection like the Lan or AA lounge, computer terminals, a shower, reading materials, TV, etc.

The other option is to to stay at the new Holiday Inn directly across from the terminal.