Chosing right collation in regard to performance

I have two tables to wich php saves text data on user demand.

My design is as follows.
Fist table:
plan varchar(1000) - latin1_swedish_ci / this colum can recive foregn letters, but are saved coded in latin
fabric_canvas varchar(20 000) - latin1_swedish_ci / text from SVG file created by fabric.js
therapy varchar(500) - utf8_unicode_ci
material varchar(500) - utf8_unicode_ci

Will i suffer from performance drop if I set first table to utf8_unicode_ci, i have alredy set mysqli connection to utf8
Shuld i change only collum plan (first table) to utf8_unicode_ci and lessen the performance that way.
Or should i change bac everything to latin since it works fine sets all the letters fine
Is performance in this case negligible.

This is an MS SQL Serer forum, so you may not find folk here that are knowledgeable on MySQL - particularly for something "subtle" like this ...

That said, I'd be interested to know what folk here think the answer would be for MS SQL Server!! I would definitely set out to keep all columns, which may be JOINed, on the same Collation.

Hello Kristen, thank you for your answer. I also got some inquiry on stack
exchange. It seams that now there is a little dilemma, just for curiosity
on milliseconds.
Maybe you should know. The question is:

I have two fields VARCHAR (20 000) and VARCHAR (40 000) So UTF-8 can't
support that ( I am limited with size in bytes). Max VARCHAR for a table is
~21000 If UTF-8 is used ! So the question would be change that to TEXT with
UTF-8 or leave it as latin VARCHAR and have automatic conversions, what
would be faster to use ? (I have 5.6.34 mysql version)

All in all, what is faster ? (Since I am obliged to have UTF-8 connection
(and overgo automatic conversion on latin tables))

A latin VARCHAR column that has to go throw automatic conversion or to
have a TEXT column with UTF-8 without automatic conversions.

Thank you for reading. I hope I have not bothered you.
Link to stackoverflow: