Hi @Anonymous ,
Do you want to avoid the effect of delegation by using "in" instead of "StartsWith" in your formula?
Firstly, I'm afraid "in" is not delegable in sharepoint list.
Search() function is not delegable in sharepoint list neither.
So if you replace startswith() with "in" or replace Filter() with Search(), you will both be affected by delegation problem.
Here's a list about the delegate functions of sharepoint list:

Here are some alternative solutions for your reference:
1)"=" is delegate in sharepoint list.
So you could use this formula which will not meet delegation problem:
Filter(draft_brandmaster,Supplier_Name=TextInput6.Text)
2)save your list data in collection.
You will not have delegation problem in collection.
ClearCollect(collection1,draft_brandmaster);
Filter(collection1,TextInput6.Text in Supplier_Name)
If your collection has meet its max limit, you could save your list data to several collections. Then filter them one by one.
For example:
ClearCollect(collection1,Filter(draft_brandmaster,ID<=10000));
ClearCollect(collection2,Filter(draft_brandmaster,ID<=20000,ID>10000));
ClearCollect(collection3,Filter(draft_brandmaster,ID<=30000,ID>20000));
ClearCollect(collection4,Filter(draft_brandmaster,ID<=40000,ID>30000));
ClearCollect(collection5,Filter(draft_brandmaster,ID<=50000,ID>40000));
ClearCollect(filtered data,
Filter(collection1,TextInput6.Text in Supplier_Name),
Filter(collection2,TextInput6.Text in Supplier_Name),
Filter(collection3,TextInput6.Text in Supplier_Name),
Filter(collection4,TextInput6.Text in Supplier_Name),
Filter(collection5,TextInput6.Text in Supplier_Name))
Best regards,