Variations problem – how hide suffix?

Hi,

In my product I use additional filed "length" to calculate price by length of product.

I have product with variations. But only half of them need calculation field (length of product). Other have constant dimenstion example 60x90 cm, 90x150 cm.

I would like to show "length filed" (to calculate) only for variations when customer must type specific lenght.

I found nice solution to my problem after reading this:
https://ww.wp.xz.cn/support/topic/assign-individual-fields-to-product-variations/

But when I add an item with constant dimention (with hidden lenght field) to cart in cart view there is still information with defalut value of filed "length".

Value 100 is default form my filed "length".

Example "Product name - 60 x 90 cm Length cm: 100". How to avoid this additional suffix affter adding item to cart?