Here are some tools that might be helpful for you in blindfolded
Download this extension(stylus-used for changing certain elements on a site): https://add0n.com/stylus.html (see top right on the website) and pin it where you can see the extensions on your browser.
Piece Style 1:
a. All pieces are visible but shaped like Go(round) pieces and retain their colour.
https://uso.kkx.one/style/156409 (click install with stylus)
b. All pieces are visible but shaped squares and retain their colour.
https://uso.kkx.one/style/161080
Piece Style 2: All pieces are visible and squared shaped but all are of white colour.
https://uso.kkx.one/style/161081
Piece Style 3: Piece are not visible at all.
https://uso.kkx.one/style/165427
(this is also available in lichess itself ->Preferences->Game display->Blindfold Chess, but this is long if you want to turn it on/off in between the game, see TIP below for solution )
TIP:
If you want to see the position with actual pieces in between the game or you want to play blindfolded only after you reach a certain number of pieces, just click on the stylus extension icon and select/deselect the styles accordingly.
Note: If you have installed multiple piece styles, only keep the piece style which you are currently using turned on and turn the rest piece styles off. (This can be done by clicking on stylus extension icon and checking the desired piece style and unchecking the rest piece styles)
I'm not related to any of the links or tools or styles and just wanted to help. Thanks!
{also if you want more customizations there are many other piece and board and site styles on the above site
and the best and very awesome customization extension PrettierLichess: https://prettierlichess.github.io/}