Arc Objects COM dll ---> Add-in? Suggestions.

[Ravichandran_M_Kaushika]

dear Readers,

good afternoon.  thank you for taking the time to read through my queries.

A brief history:

1. We developed a COM arcobjects toolbar with commands, tools, and menu in 2008 to INTERFACE with our enterprise Customer Service Toolkit (CSTK) - a client tool that had ArcToolbar and other windows components.
2. Our toolbar was written using VB.NET. and we were continuously upgrading this toolbar to the latest version of ArcGIS, windows OS,  CSTK, and .net framework every few years when there was an enterprise wide (nation wide) upgrade.
3. Right now CSTK is replaced by another web based tool that uses REST services and other web protocols.
4. Our toolbar needs to be 'upgraded' from COM dll ArcObjects to something new...

Info:  OUR toolbar would do the following:

1. import feature and attribute data from CSTK,
2. modify the spatial data using Microsoft system graphics, ArcGIS tools and menus, attribute data using VB forms, 
3. store most of the information in file geo-database and in MS Access,  and
4. feed the relevant modified data to another program.

One of the available options to avoid COM registrations and issues would be add-in.

Our general direction and team strengths:

1. We understand that Arcgis 10.7.1 has better support for lidar data (than 10.5) and so does ArcGIS Pro 2.5.x.
2. Since our users in the field are familiar with ArcGIS 10.5 and 10.7.1 - we want to delay introducing tools in ArcGIS Pro by 12 months to 18 months.
3. Our development team has experience in VB.NET (rumors plenty about VB.NET's reduced support), C#, Python, HTML, JavaScript, XML, JSON, and related technologies.
4. We want to create a client tool as our users might be in regions of limited internet connectivity.

Questions:

1. Pardon my ignorance about Add-ins - will be watching videos about add-ins.  Does Add-in support our requirements of the toolbar (not CSTK) that we are planning to write for arcgis 10.7.1 and may be ArcGIS Pro later on.
2. Is ESRI's suggested route Python or C# for developing Add-ins ensuring that we are not caught on the wrong foot in the future - we have staff knowledgeable in both.

Any guidance to the above questions and beyond would be greatly beneficial.  

thank you in advance.

thanks and regards

Ravi.

[Ravichandran_M_Kaushika]

I wanted to add that i need to create Windows Forms (assuming management does not want Web App Builder) that would let users choose certain parameters before doing additional work.

thanks and regards

Ravi Kaushika

[Ravichandran_M_Kaushika]

Thanks to ESRI staff members.

Creating Toolbar using Add-in was easier than the COM route.