Litton 92 TMIX vs RNAV update

[LGB]

I have looked in the manual, but I am still in doubt, so you LTN92 experts out there, please read on.

If you enable both TMIX and RNAV, RNAV will of course take priority over TMIX. But what happens when RNAV updating stops - you go to TMIX (if enabled). In TMIX, is it "pure" TMIX, or is it including the latest received RNAV correction vector? Going between TMIX and RNAV, especially after several hours of flying, seems to rock the boat, left and right of track, ATC can ask to confirm you are inbound a certain station, and the zigzakking course cannot be the best for fuel economy!

The manual seems to confirm this, but it seems impractical to discard a good DME/DME RNAV update minutes after is lost. The manual says when RNAV is lost, it goes to TMIX, and TMIX is defined as the mix between the three INS positions. No mention of any RNAV correction?

Is it the same if RNAV is enabled, but TMIX is disabled? In that case, losing the DME update means reverting to pure INS. But does it remember the latest RNAV update now (since in is not going into TMIX)?

[Roadtrip]

Reference "The Litton Pilot's Guide TP92-0413G, Rev 10"

"When the FLUSH mode is selected, all position updates (GPS, RNAV, TMIX, MANUAL) will be zeroed and all three automatic updates will be disabled. The system will use inertial position for horizontal guidance." see page 6-26

"Disabling TMIX assumes a problem with the triple mix solution and will flush the TMIX corrections from that INU (this has no affect on other INUs and does not flush previous GPS or RNAV corrections)." page 6-18

So, the answer updates are not flushed unless the operator commands it throught he FLUSH MODE.

As far as the snaking goes when coasting in and getting a RNAV (DME update), there is an "EASY ON/OFF STEERING" mode:
"To enable a smooth and easy trasition, the HSI/Autopilot steering to recapture desired Track is limited ot a maximum rate of 1.9 nm/min. This "Easy On/Off Steering" causes shallower slower maneuvering during track recapture." page 6-1