many rows and spans for a datatable row and for each row ( more than 1000 rows?

Hi webix!

I tried to do something lke this:

https://webix.com/snippet/aaf39c82

but i had some performance troubles:

→ How link two rows ? ( on filter i loose one)
→ How template span config for EACH product (I can do this by sending by server_side spans arrays but app get too slowly)
→ is it possible to make a “sub datatable” in a cell that will be easier than spans…

As you can see i have two solutions, make “sub datatable” for packages or using spans.

What is better and how do it well?

thanks