@Nathalie - the previous discussion was on banking things - but as to your 1) point: 2FA with Google Authenticator - you can replace GA and import the TOTP codes into Aegis. Even use Aegis then as 2FA to login to a Google account. Or what is the painpoint in using 2FA specifically?
as to 2) the feedback on PayTM was positive as far as 2022 (1, 2). You’d want to check your microG settings for disabled options if something fails to run.