My group recently migrated from classic to New Google Sites. There were many things I was doing with classic sites and/or apps script's Sites Service I can't do
ip-geolocation
figsize
railsapps
go-reflect
selenium-iedriver
tiingo
gulp
uiculture
filenet-cpe
github-copilot
changelist
outlook-addin
semantic-mediawiki
flux-machine-learning
jcmd
asp.net-core-middleware
point-in-polygon
libvirt
infopath-forms-services
anchor-protocol
recurring-events
jquery-1.7
zpt
wss
spring-social
javafx-2
proxypass
jsonrpc4j
coin-or
fiware-wilma