Denny_Crane_747. I am a real life (retired) Learjet pilot with 12,000+ hours in various Learjet Models including 8,000 in Lear 35s. I am a volunteer beta testers for the FSW 35a. I do not work for FSW but I love flying their FSW LR35a.
I monitor and post on Discord's Flysimware LLC giving and receiving advice about the FSW LR35a and comparing the MSFS experience to flying the actual aircraft.
I fly the sim version of the LR35a almost every day and use all three versions of the GPS systems frequently because I fly often to confirm or deny (if that is the proper word) what people are saying about the LR35a software.
The TDS version of the 750 has had issues that in the recent weeks that the FSW devs had tried, and suceeded, to improve on within the limitations of what the TDSSIM folks have done and ASOBO limitations.
As of this date the TDS 750 No Longer has problems with many of the issues you have listed. I usually fly using the TDS GTNXi unless I am testing and, with a minor exception that the TDSSIM folks are aware of, the 750 is working well. (The 'SMART GLIDE' message advisory won't clear any time the aircraft is above 36,000'. The TDSSIM folks are aware of the cause and it will be fixed in the next update.
If you don't want to hear advice or help on how to correct some or all of you issues, please stop reading now and move on. By the tone of your previous posts I am not sure you do want help as you already 'know what you are doing'.
1. The graphic you are quoting saying the ILS cannot be intercepted in the manner we are accustomed to is out of date and not really true anyway.
2. The Primary reason that folds have issues with the TDS, and any other GPS/NAV system is that the FSW 35a and the Nav System MUST both be up-to-date with the current version. Every update in one set of software can cause the need for the 3rd party vendors to update their software and on and on back and forth. Both sides are working hard to keep up.
3. The next important reason that folks have problems with the TDS is that the FSW 35a and the TDS GTNXi MUST both be installed in a specific manner or problems WILL exist. Namely, regardless of any instructions on how to install the aircraft AND the GPS systems, any OLD previous version of the software systems must be removed from the Community folder before running the install program. The FSW install .exe is designed to remove all the old stuff but sometimes fails to remove hidden code or code that is duplicated in more than one place. But bad, duplicate, or corrupted code is not always removed by the install software. Dare I say 'frequently'.
4. I always go to General Options Data and clear the software cache anytime I do a MSFS 2020 or 3rd party app update.
5. If you have any 3rd party liveries for a particular aircraft in the Community folder AND the same livery is 'in game' for an aircraft there is a good chance of a conflict. To test for conflicts, remove 3rd party liveries from Community and see if that livery is still available in the 'Select Aircraft' menu at start of World Map. If it is there do not put it back in Community.
My current directory name in the Community Directory for the FSW 35a is Community\flysimware-learjet-35a and the manifest.json file AND the MSFS 2020 'Content Manager' both report Package Version 1.4.0.
The current directory name for the TDS 750 is Community\tda-gtnxi-gauge and its manifest.json 'Package Version' as well as the MSFS 'Content Manager' both report 1.0.14.
The bizarre behavior you are reporting indicates to me you have a major install issue somewhere and that making certain your versions are up-to-date and deleting any old versions in Community will go a long way toward solving your problems (with the LR35a 🙂 )
Give the suggestions a try. Trust me on this.
Cheers Headwind (on Flysimware LLC: Discord)