error when trying to join many upset plots in only one plot using grid.arrange in r

I'm trying to join many upset plots in only one image in r, I can generate the plots individually but when I use grid.arrange (from gridExtra) to join them like this:

grid.arrange(plot1, plot2)

it gives this error:

Error in gList(...): only 'grobs' allowed in 'gList'

I think this is happening because the plot is an 'upset' class, I tried to transform them into a ggplot using ggplotGrob() but it gives:

Error in UseMethod("ggplot_build"): no applicable method for 'ggplot_build' applied to an object of class upset"

upsetR makes a custom object that combines ggplot2 elements but is not itself a ggplot2 object. I'm curious if there's a better way, but the only approach I could get to work was to go

upsetR object -> render image -> convert image to ggplot2 with magick -> combine using gridExtra or patchwork.

# make upsetR object
library(UpSetR)
movies <- read.csv(system.file("extdata", "movies.csv", package = "UpSetR"), 
                   header = T, sep = ";")

up <- upset(movies, sets = c("Action", "Adventure", "Comedy", "Drama", "Mystery", 
                             "Thriller", "Romance", "War", "Western"), mb.ratio = c(0.55, 0.45), order.by = "freq")

Then:

# render as image
up_img <- ragg::agg_png("up_ragg.png", width = 800, height = 500)
print(up)
dev.off()

# put image in ggplot2 object
library(magick)
up_gg <- image_read("up_ragg.png") |> image_ggplot()

# compose ggplot2 object(s) 
library(patchwork)
up_gg | up_gg